// Automatically generated by genmatrix.py // 8-bit Load Group if (pla[17] & ~pla[50]) begin if (M1 & T1) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=op54; ctl_reg_gp_hilo={~rsel3,rsel3}; /* Write 8-bit GP register */ ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; setM1=1; end end if (pla[61] & ~pla[58] & ~pla[59]) begin if (M1 & T1) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=op54; ctl_reg_gp_hilo={~rsel3,rsel3}; /* Write 8-bit GP register */ ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_sw_2u=1; ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_op1_oe=1; /* OP1 latch */ end if (M1 & T4) begin validPLA=1; setM1=1; ctl_reg_gp_sel=op21; ctl_reg_gp_hilo={~rsel0,rsel0};/* Read 8-bit GP register selected by op[2:0] */ ctl_reg_out_hi=~rsel0; ctl_reg_out_lo=rsel0; ctl_sw_2u=~rsel0; ctl_sw_2d=rsel0; /* Enable register gate based on the rsel0 */ /* Controlled by register gate */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op1_sel_bus=1; /* Internal bus */ end end if (use_ixiy & pla[58]) begin if (M1 & T1) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=op54; ctl_reg_gp_hilo={~rsel3,rsel3}; /* Write 8-bit GP register */ ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; nextM=1; end if (M3 & T1) begin ixy_d=1; /* Compute WZ=IX+d */ end if (M3 & T2) begin ixy_d=1; /* Compute WZ=IX+d */ end if (M3 & T3) begin ixy_d=1; /* Compute WZ=IX+d */ end if (M3 & T4) begin ixy_d=1; /* Compute WZ=IX+d */ end if (M3 & T5) begin nextM=1; ctl_mRead=1; ixy_d=1; /* Compute WZ=IX+d */ end end if (~use_ixiy & pla[58]) begin if (M1 & T1) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=op54; ctl_reg_gp_hilo={~rsel3,rsel3}; /* Write 8-bit GP register */ ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1; /* Read 16-bit HL, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; end if (M2 & T3) begin fMRead=1; setM1=1; end if (M4 & T1) begin fMRead=1; ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M4 & T2) begin fMRead=1; end if (M4 & T3) begin fMRead=1; setM1=1; end end if (use_ixiy & pla[59]) begin if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; nextM=1; end if (M3 & T1) begin ixy_d=1; /* Compute WZ=IX+d */ end if (M3 & T2) begin ixy_d=1; /* Compute WZ=IX+d */ end if (M3 & T3) begin ixy_d=1; /* Compute WZ=IX+d */ end if (M3 & T4) begin ixy_d=1; /* Compute WZ=IX+d */ end if (M3 & T5) begin nextM=1; ctl_mWrite=1; ixy_d=1; /* Compute WZ=IX+d */ end end if (~use_ixiy & pla[59]) begin if (M1 & T4) begin validPLA=1; nextM=1; ctl_mWrite=1; ctl_reg_gp_sel=op21; ctl_reg_gp_hilo={~rsel0,rsel0};/* Read 8-bit GP register selected by op[2:0] */ ctl_reg_out_hi=~rsel0; ctl_reg_out_lo=rsel0; ctl_sw_2u=~rsel0; ctl_sw_2d=rsel0; /* Enable register gate based on the rsel0 */ /* Controlled by register gate */ ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ end if (M2 & T1) begin fMWrite=1; ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1; /* Read 16-bit HL, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMWrite=1; end if (M2 & T3) begin fMWrite=1; setM1=1; end if (M4 & T1) begin fMWrite=1; ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ ctl_reg_gp_sel=op21; ctl_reg_gp_hilo={~rsel0,rsel0};/* Read 8-bit GP register selected by op[2:0] */ ctl_reg_out_hi=~rsel0; ctl_reg_out_lo=rsel0; ctl_sw_2u=~rsel0; ctl_sw_2d=rsel0; /* Enable register gate based on the rsel0 */ /* Controlled by register gate */ ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ end if (M4 & T2) begin fMWrite=1; end if (M4 & T3) begin fMWrite=1; setM1=1; end end if (pla[40]) begin if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; nextM=1; ctl_mRead=1; end if (M3 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ixy_d=1; /* Compute WZ=IX+d */ end if (M3 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ ixy_d=1; /* Compute WZ=IX+d */ end if (M3 & T3) begin fMRead=1; ixy_d=1; /* Compute WZ=IX+d */ end if (M3 & T4) begin ixy_d=1; /* Compute WZ=IX+d */ end if (M3 & T5) begin nextM=1; ctl_mWrite=1; ixy_d=1; /* Compute WZ=IX+d */ end end if (pla[50] & ~pla[40]) begin if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; nextM=1; ctl_mWrite=1; end if (M3 & T1) begin fMWrite=1; ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1; /* Read 16-bit HL, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M3 & T2) begin fMWrite=1; end if (M3 & T3) begin fMWrite=1; setM1=1; end if (M4 & T1) begin fMWrite=1; ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M4 & T2) begin fMWrite=1; end if (M4 & T3) begin fMWrite=1; setM1=1; end end if (pla[8] & pla[13]) begin if (M1 & T4) begin validPLA=1; nextM=1; ctl_mWrite=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b10; ctl_reg_out_hi=1; /* From the register file onto the db2 (sw2 + ALU) */ ctl_sw_2u=1; ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ end if (M2 & T1) begin fMWrite=1; ctl_reg_gp_sel=op54; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1; /* Read 16-bit general purpose register, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMWrite=1; ctl_reg_sys_we=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4u=1; /* Write 16-bit WZ, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMWrite=1; setM1=1; end end if (pla[8] & ~pla[13]) begin if (M1 & T1) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b10; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_gp_sel=op54; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1; /* Read 16-bit general purpose register, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4u=1; /* Write 16-bit WZ, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; setM1=1; end end if (pla[38] & pla[13]) begin if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; nextM=1; ctl_mRead=1; ctl_reg_sys_we_lo=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={ctl_reg_sys_hilo[1],1'b1}; /* Selecting only Z */ ctl_reg_in_lo=1; /* From the ALU side into the register file low byte only */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M3 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M3 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M3 & T3) begin fMRead=1; nextM=1; ctl_mWrite=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1; /* Select 16-bit WZ */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_reg_sys_we_hi=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={1'b1,ctl_reg_sys_hilo[0]}; /* Selecting only W */ ctl_reg_in_hi=1; /* From the ALU side into the register file high byte only */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M4 & T1) begin fMWrite=1; ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b10; ctl_reg_out_hi=1; /* From the register file onto the db2 (sw2 + ALU) */ ctl_sw_2u=1; ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ end if (M4 & T2) begin fMWrite=1; ctl_reg_sys_we=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4u=1; /* Write 16-bit WZ, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M4 & T3) begin fMWrite=1; setM1=1; end end if (pla[38] & ~pla[13]) begin if (M1 & T1) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b10; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; nextM=1; ctl_mRead=1; ctl_reg_sys_we_lo=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={ctl_reg_sys_hilo[1],1'b1}; /* Selecting only Z */ ctl_reg_in_lo=1; /* From the ALU side into the register file low byte only */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M3 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M3 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M3 & T3) begin fMRead=1; nextM=1; ctl_mRead=1; ctl_reg_sys_we_hi=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={1'b1,ctl_reg_sys_hilo[0]}; /* Selecting only W */ ctl_reg_in_hi=1; /* From the ALU side into the register file high byte only */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M4 & T1) begin fMRead=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1; /* Select 16-bit WZ */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M4 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4u=1; /* Write 16-bit WZ, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M4 & T3) begin fMRead=1; setM1=1; end end if (pla[83]) begin if (M1 & T1) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b10; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_pf_sel=`PFSEL_IFF2; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; end if (M1 & T2) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b01; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_oe=1; /* Enable FLAGT onto the data bus */ end if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; ctl_reg_sel_ir=1; ctl_reg_sys_hilo={~op3,op3}; ctl_sw_4u=1; /* Read either I or R based on op3 (0 or 1) */ ctl_reg_out_hi=~rsel3; ctl_reg_out_lo=rsel3; ctl_sw_2u=~rsel3; ctl_sw_2d=rsel3; /* Enable register gate based on the rsel3 */ /* Controlled by register gate */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; end if (M1 & T5) begin setM1=1; end end if (pla[57]) begin if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; ctl_reg_sys_we=1; ctl_reg_sel_ir=1; ctl_reg_sys_hilo={~op3,op3}; ctl_sw_4d=1; /* Write either I or R based on op3 (0 or 1) */ ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_sw_2u=1; ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_op1_oe=1; /* OP1 latch */ end if (M1 & T5) begin setM1=1; end end // 16-bit Load Group if (pla[7]) begin if (M1 & T1) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=op54; ctl_reg_gp_hilo=2'b10; /* Write 8-bit GP register high byte */ ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_reg_use_sp=1; /* For 16-bit loads: use SP instead of AF */ end if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; nextM=1; ctl_mRead=1; end if (M3 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_reg_gp_we=1; ctl_reg_gp_sel=op54; ctl_reg_gp_hilo=2'b01; /* Write 8-bit GP register low byte */ ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_reg_use_sp=1; /* For 16-bit loads: use SP instead of AF */ end if (M3 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M3 & T3) begin fMRead=1; setM1=1; end end if (pla[30] & pla[13]) begin if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; nextM=1; ctl_mRead=1; ctl_reg_sys_we_lo=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={ctl_reg_sys_hilo[1],1'b1}; /* Selecting only Z */ ctl_reg_in_lo=1; /* From the ALU side into the register file low byte only */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M3 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M3 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M3 & T3) begin fMRead=1; nextM=1; ctl_mWrite=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1; /* Select 16-bit WZ */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_reg_sys_we_hi=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={1'b1,ctl_reg_sys_hilo[0]}; /* Selecting only W */ ctl_reg_in_hi=1; /* From the ALU side into the register file high byte only */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M4 & T1) begin fMWrite=1; ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ ctl_reg_gp_sel=op54; ctl_reg_gp_hilo=2'b01; /* Read 8-bit GP register low byte */ ctl_reg_out_lo=1; /* From the register file onto the db1 (sw2 + FLAGT + sw1) */ ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ end if (M4 & T2) begin fMWrite=1; ctl_reg_sys_we=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4u=1; /* Write 16-bit WZ, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M4 & T3) begin fMWrite=1; nextM=1; ctl_mWrite=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1; /* Select 16-bit WZ */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M5 & T1) begin fMWrite=1; ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ ctl_reg_gp_sel=op54; ctl_reg_gp_hilo=2'b10; /* Read 8-bit GP register high byte */ ctl_reg_out_hi=1; /* From the register file onto the db2 (sw2 + ALU) */ ctl_sw_2u=1; ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ end if (M5 & T2) begin fMWrite=1; ctl_reg_sys_we=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4u=1; /* Write 16-bit WZ, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M5 & T3) begin fMWrite=1; setM1=1; end end if (pla[30] & ~pla[13]) begin if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; nextM=1; ctl_mRead=1; ctl_reg_sys_we_lo=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={ctl_reg_sys_hilo[1],1'b1}; /* Selecting only Z */ ctl_reg_in_lo=1; /* From the ALU side into the register file low byte only */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M3 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M3 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M3 & T3) begin fMRead=1; nextM=1; ctl_mRead=1; ctl_reg_sys_we_hi=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={1'b1,ctl_reg_sys_hilo[0]}; /* Selecting only W */ ctl_reg_in_hi=1; /* From the ALU side into the register file high byte only */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M4 & T1) begin fMRead=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1; /* Select 16-bit WZ */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M4 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4u=1; /* Write 16-bit WZ, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M4 & T3) begin fMRead=1; nextM=1; ctl_mRead=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=op54; ctl_reg_gp_hilo=2'b01; /* Write 8-bit GP register low byte */ ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M5 & T1) begin fMRead=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1; /* Select 16-bit WZ */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M5 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4u=1; /* Write 16-bit WZ, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M5 & T3) begin fMRead=1; setM1=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=op54; ctl_reg_gp_hilo=2'b10; /* Write 8-bit GP register high byte */ ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end end if (pla[31] & pla[33]) begin if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; nextM=1; ctl_mRead=1; ctl_reg_sys_we_lo=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={ctl_reg_sys_hilo[1],1'b1}; /* Selecting only Z */ ctl_reg_in_lo=1; /* From the ALU side into the register file low byte only */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M3 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M3 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M3 & T3) begin fMRead=1; nextM=1; ctl_mWrite=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1; /* Select 16-bit WZ */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_reg_sys_we_hi=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={1'b1,ctl_reg_sys_hilo[0]}; /* Selecting only W */ ctl_reg_in_hi=1; /* From the ALU side into the register file high byte only */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M4 & T1) begin fMWrite=1; ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ ctl_reg_gp_sel=op54; ctl_reg_gp_hilo=2'b01; /* Read 8-bit GP register low byte */ ctl_reg_out_lo=1; /* From the register file onto the db1 (sw2 + FLAGT + sw1) */ ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ ctl_reg_use_sp=1; /* For 16-bit loads: use SP instead of AF */ end if (M4 & T2) begin fMWrite=1; ctl_reg_sys_we=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4u=1; /* Write 16-bit WZ, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M4 & T3) begin fMWrite=1; nextM=1; ctl_mWrite=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1; /* Select 16-bit WZ */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M5 & T1) begin fMWrite=1; ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ ctl_reg_gp_sel=op54; ctl_reg_gp_hilo=2'b10; /* Read 8-bit GP register high byte */ ctl_reg_out_hi=1; /* From the register file onto the db2 (sw2 + ALU) */ ctl_sw_2u=1; ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ ctl_reg_use_sp=1; /* For 16-bit loads: use SP instead of AF */ end if (M5 & T2) begin fMWrite=1; ctl_reg_sys_we=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4u=1; /* Write 16-bit WZ, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M5 & T3) begin fMWrite=1; setM1=1; end end if (pla[31] & ~pla[33]) begin if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; nextM=1; ctl_mRead=1; ctl_reg_sys_we_lo=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={ctl_reg_sys_hilo[1],1'b1}; /* Selecting only Z */ ctl_reg_in_lo=1; /* From the ALU side into the register file low byte only */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M3 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M3 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M3 & T3) begin fMRead=1; nextM=1; ctl_mRead=1; ctl_reg_sys_we_hi=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={1'b1,ctl_reg_sys_hilo[0]}; /* Selecting only W */ ctl_reg_in_hi=1; /* From the ALU side into the register file high byte only */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M4 & T1) begin fMRead=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1; /* Select 16-bit WZ */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M4 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4u=1; /* Write 16-bit WZ, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M4 & T3) begin fMRead=1; nextM=1; ctl_mRead=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=op54; ctl_reg_gp_hilo=2'b01; /* Write 8-bit GP register low byte */ ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_reg_use_sp=1; /* For 16-bit loads: use SP instead of AF */ end if (M5 & T1) begin fMRead=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1; /* Select 16-bit WZ */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M5 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4u=1; /* Write 16-bit WZ, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M5 & T3) begin fMRead=1; setM1=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=op54; ctl_reg_gp_hilo=2'b10; /* Write 8-bit GP register high byte */ ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_reg_use_sp=1; /* For 16-bit loads: use SP instead of AF */ end end if (pla[5]) begin if (M1 & T4) begin validPLA=1; ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1; /* Read 16-bit HL, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M1 & T5) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_use_sp=1; ctl_sw_4u=1; /* Write 16-bit SP, enable SW4 upstream */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M1 & T6) begin setM1=1; end end if (pla[23] & pla[16]) begin if (M1 & T4) begin validPLA=1; end if (M1 & T5) begin nextM=1; ctl_mWrite=1; ctl_reg_use_sp=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1;/* Read 16-bit SP, enable SW4 downstream */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T1) begin fMWrite=1; ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_apin_mux=1; /* Apin sourced from incrementer */ ctl_reg_gp_sel=op54; ctl_reg_gp_hilo=2'b10; /* Read 8-bit GP register high byte */ ctl_reg_out_hi=1; /* From the register file onto the db2 (sw2 + ALU) */ ctl_sw_2u=1; ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ end if (M2 & T2) begin fMWrite=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_use_sp=1; ctl_sw_4u=1; /* Write 16-bit SP, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMWrite=1; nextM=1; ctl_mWrite=1; ctl_reg_use_sp=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1;/* Read 16-bit SP, enable SW4 downstream */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M3 & T1) begin fMWrite=1; ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_apin_mux=1; /* Apin sourced from incrementer */ ctl_reg_gp_sel=op54; ctl_reg_gp_hilo=2'b01; /* Read 8-bit GP register low byte */ ctl_reg_out_lo=1; /* From the register file onto the db1 (sw2 + FLAGT + sw1) */ ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ end if (M3 & T2) begin fMWrite=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_use_sp=1; ctl_sw_4u=1; /* Write 16-bit SP, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M3 & T3) begin fMWrite=1; setM1=1; end end if (pla[23] & ~pla[16]) begin if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_use_sp=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1;/* Read 16-bit SP, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_use_sp=1; ctl_sw_4u=1; /* Write 16-bit SP, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; nextM=1; ctl_mRead=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=op54; ctl_reg_gp_hilo=2'b01; /* Write 8-bit GP register low byte */ ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M3 & T1) begin fMRead=1; ctl_reg_use_sp=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1;/* Read 16-bit SP, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M3 & T2) begin fMRead=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_use_sp=1; ctl_sw_4u=1; /* Write 16-bit SP, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M3 & T3) begin fMRead=1; setM1=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=op54; ctl_reg_gp_hilo=2'b10; /* Write 8-bit GP register high byte */ ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end end // Exchange, Block Transfer and Search Groups if (pla[2]) begin if (M1 & T2) begin ctl_reg_ex_de_hl=1; /* EX DE,HL */ end if (M1 & T4) begin validPLA=1; setM1=1; end end if (pla[39]) begin if (M1 & T2) begin ctl_reg_ex_af=1; /* EX AF,AF' */ end if (M1 & T4) begin validPLA=1; setM1=1; end end if (pla[1]) begin if (M1 & T2) begin ctl_reg_exx=1; /* EXX */ end if (M1 & T4) begin validPLA=1; setM1=1; end end if (pla[10]) begin if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_use_sp=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1;/* Read 16-bit SP, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_use_sp=1; ctl_sw_4u=1; /* Write 16-bit SP, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; nextM=1; ctl_mRead=1; ctl_reg_sys_we_lo=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={ctl_reg_sys_hilo[1],1'b1}; /* Selecting only Z */ ctl_reg_in_lo=1; /* From the ALU side into the register file low byte only */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M3 & T1) begin fMRead=1; ctl_reg_use_sp=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1;/* Read 16-bit SP, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M3 & T2) begin fMRead=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_use_sp=1; ctl_sw_4u=1; /* Write 16-bit SP, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M3 & T3) begin fMRead=1; ctl_reg_sys_we_hi=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={1'b1,ctl_reg_sys_hilo[0]}; /* Selecting only W */ ctl_reg_in_hi=1; /* From the ALU side into the register file high byte only */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M3 & T4) begin nextM=1; ctl_mWrite=1; ctl_reg_use_sp=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1;/* Read 16-bit SP, enable SW4 downstream */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M4 & T1) begin fMWrite=1; ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_apin_mux=1; /* Apin sourced from incrementer */ ctl_reg_gp_sel=op54; ctl_reg_gp_hilo=2'b10; /* Read 8-bit GP register high byte */ ctl_reg_out_hi=1; /* From the register file onto the db2 (sw2 + ALU) */ ctl_sw_2u=1; ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ end if (M4 & T2) begin fMWrite=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_use_sp=1; ctl_sw_4u=1; /* Write 16-bit SP, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M4 & T3) begin fMWrite=1; nextM=1; ctl_mWrite=1; ctl_reg_use_sp=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1;/* Read 16-bit SP, enable SW4 downstream */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M5 & T1) begin fMWrite=1; ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_apin_mux=1; /* Apin sourced from incrementer */ ctl_reg_gp_sel=op54; ctl_reg_gp_hilo=2'b01; /* Read 8-bit GP register low byte */ ctl_reg_out_lo=1; /* From the register file onto the db1 (sw2 + FLAGT + sw1) */ ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ end if (M5 & T2) begin fMWrite=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_use_sp=1; ctl_sw_4u=1; /* Write 16-bit SP, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M5 & T3) begin fMWrite=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1; /* Select 16-bit WZ */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M5 & T4) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b11; ctl_sw_4u=1; /* Write 16-bit HL, enable SW4 upstream */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M5 & T5) begin setM1=1; end end if (pla[0]) begin begin nonRep=1; /* Non-repeating block instruction */ end end if (pla[12]) begin if (M1 & T1) begin ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_pf_sel=`PFSEL_REP; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; ctl_flags_use_cf2=1; end if (M1 & T2) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b01; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_oe=1; /* Enable FLAGT onto the data bus */ end if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1; /* Read 16-bit HL, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b11; ctl_sw_4u=1; /* Write 16-bit HL, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=op3; /* Decrement if op3 is set; increment otherwise */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; nextM=1; ctl_mWrite=1; ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_flags_cf_set|=ctl_alu_op_low; ctl_flags_cf_cpl|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_hf_we=1; ctl_flags_cf2_we=1; end if (M3 & T1) begin fMWrite=1; ctl_reg_gp_sel=`GP_REG_DE; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1; /* Read 16-bit DE, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_flags_cf_set|=ctl_alu_op_low; ctl_flags_cf_cpl|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_use_cf2=1; end if (M3 & T2) begin fMWrite=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_DE; ctl_reg_gp_hilo=2'b11; ctl_sw_4u=1; /* Write 16-bit BC, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=op3; /* Decrement if op3 is set; increment otherwise */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M3 & T3) begin fMWrite=1; ctl_reg_gp_sel=`GP_REG_BC; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1; /* Read 16-bit BC, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M3 & T4) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_BC; ctl_reg_gp_hilo=2'b11; ctl_sw_4u=1; /* Write 16-bit BC, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ ctl_repeat_we=1; /* Update repeating flag latch with BC=1 status */ end if (M3 & T5) begin nextM=1; setM1=nonRep | ~repeat_en; end if (M4 & T1) begin ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M4 & T2) begin ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M4 & T3) begin ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M4 & T4) begin ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M4 & T5) begin setM1=1; end end if (pla[11]) begin if (M1 & T1) begin ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_op1_sel_zero=1; /* Zero */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_sel_op2_neg=1; ctl_flags_cf_set|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_xy_we=1; ctl_flags_pf_we=1; ctl_pf_sel=`PFSEL_REP; ctl_flags_nf_we=1; ctl_flags_nf_set=1; ctl_flags_use_cf2=1; end if (M1 & T2) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b01; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_oe=1; /* Enable FLAGT onto the data bus */ ctl_flags_hf_cpl=flags_nf; end if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1; /* Read 16-bit HL, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b11; ctl_sw_4u=1; /* Write 16-bit HL, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=op3; /* Decrement if op3 is set; increment otherwise */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; nextM=1; ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_sel_op2_neg=1; ctl_flags_cf_set|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_hf_we=1; ctl_flags_cf2_we=1; end if (M3 & T1) begin ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_sel_op2_neg=1; ctl_flags_cf_set|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_sz_we=1; ctl_flags_use_cf2=1; end if (M3 & T3) begin ctl_reg_gp_sel=`GP_REG_BC; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1; /* Read 16-bit BC, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M3 & T4) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_BC; ctl_reg_gp_hilo=2'b11; ctl_sw_4u=1; /* Write 16-bit BC, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ ctl_repeat_we=1; /* Update repeating flag latch with BC=1 status */ end if (M3 & T5) begin nextM=1; setM1=nonRep | ~repeat_en | flags_zf; end if (M4 & T1) begin ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M4 & T2) begin ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M4 & T3) begin ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M4 & T4) begin ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M4 & T5) begin setM1=1; end end // 8-bit Arithmetic and Logic Group if (pla[65] & ~pla[52]) begin if (M1 & T1) begin /* Which register to be written is decided elsewhere */ ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_sw_2u=1; ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_state_alu=1; /* Assert the ALU PLA modifier to determine operation */ ctl_flags_sz_we=1; ctl_flags_cf_we=1; end if (M1 & T2) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b01; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_oe=1; /* Enable FLAGT onto the data bus */ ctl_state_alu=1; /* Assert the ALU PLA modifier to determine operation */ ctl_flags_hf_cpl=flags_nf; ctl_flags_cf_cpl=flags_nf; end if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; setM1=1; ctl_reg_gp_sel=op21; ctl_reg_gp_hilo={~rsel0,rsel0};/* Read 8-bit GP register selected by op[2:0] */ ctl_reg_out_hi=~rsel0; ctl_reg_out_lo=rsel0; ctl_sw_2u=~rsel0; ctl_sw_2d=rsel0; /* Enable register gate based on the rsel0 */ /* Controlled by register gate */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_state_alu=1; /* Assert the ALU PLA modifier to determine operation */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; end end if (pla[64]) begin if (M1 & T1) begin /* Which register to be written is decided elsewhere */ ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_sw_2u=1; ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_state_alu=1; /* Assert the ALU PLA modifier to determine operation */ ctl_flags_sz_we=1; ctl_flags_cf_we=1; end if (M1 & T2) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b01; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_oe=1; /* Enable FLAGT onto the data bus */ ctl_state_alu=1; /* Assert the ALU PLA modifier to determine operation */ ctl_flags_hf_cpl=flags_nf; ctl_flags_cf_cpl=flags_nf; end if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; ctl_reg_gp_sel=op21; ctl_reg_gp_hilo={~rsel0,rsel0};/* Read 8-bit GP register selected by op[2:0] */ ctl_reg_out_hi=~rsel0; ctl_reg_out_lo=rsel0; ctl_sw_2u=~rsel0; ctl_sw_2d=rsel0; /* Enable register gate based on the rsel0 */ /* Controlled by register gate */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_state_alu=1; /* Assert the ALU PLA modifier to determine operation */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; end if (M2 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_state_alu=1; /* Assert the ALU PLA modifier to determine operation */ end if (M2 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; setM1=1; ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_state_alu=1; /* Assert the ALU PLA modifier to determine operation */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; end end if (use_ixiy & pla[52]) begin if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; nextM=1; end if (M3 & T1) begin ixy_d=1; /* Compute WZ=IX+d */ end if (M3 & T2) begin ixy_d=1; /* Compute WZ=IX+d */ end if (M3 & T3) begin ixy_d=1; /* Compute WZ=IX+d */ end if (M3 & T4) begin ixy_d=1; /* Compute WZ=IX+d */ end if (M3 & T5) begin nextM=1; ctl_mRead=1; ixy_d=1; /* Compute WZ=IX+d */ end end if (~use_ixiy & pla[52]) begin if (M1 & T1) begin /* Which register to be written is decided elsewhere */ ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_sw_2u=1; ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_state_alu=1; /* Assert the ALU PLA modifier to determine operation */ ctl_flags_sz_we=1; ctl_flags_cf_we=1; end if (M1 & T2) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b01; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_oe=1; /* Enable FLAGT onto the data bus */ ctl_state_alu=1; /* Assert the ALU PLA modifier to determine operation */ ctl_flags_hf_cpl=flags_nf; ctl_flags_cf_cpl=flags_nf; end if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1; /* Read 16-bit HL, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4u=1; /* Write 16-bit WZ, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; setM1=1; ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_state_alu=1; /* Assert the ALU PLA modifier to determine operation */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; end if (M4 & T1) begin fMRead=1; ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M4 & T2) begin fMRead=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M4 & T3) begin fMRead=1; setM1=1; ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_state_alu=1; /* Assert the ALU PLA modifier to determine operation */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; end end if (pla[66] & ~pla[53]) begin if (M1 & T1) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=op54; ctl_reg_gp_hilo={~rsel3,rsel3}; /* Write 8-bit GP register */ ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_sw_2u=1; ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_pf_we=1; ctl_pf_sel=`PFSEL_V; ctl_flags_use_cf2=1; end if (M1 & T2) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b01; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_oe=1; /* Enable FLAGT onto the data bus */ ctl_flags_hf_cpl=flags_nf; end if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; setM1=1; if (op4 & op5 & ~op3) begin ctl_bus_zero_oe=1; end /* Trying to read flags? Put 0 on the bus instead. */ if (~(op4 & op5 & ~op3)) begin ctl_reg_gp_sel=op54; ctl_reg_gp_hilo={~rsel3,rsel3}; end /* Read 8-bit GP register */ ctl_reg_out_hi=~rsel3; ctl_reg_out_lo=rsel3; ctl_sw_2u=~rsel3; ctl_sw_2d=rsel3; /* Enable register gate based on the rsel3 */ /* Controlled by register gate */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_zero=1; /* Zero */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; ctl_flags_cf_set=1; /* Set CF going into the ALU core */ ctl_flags_cf2_we=1; end end if (pla[75]) begin if (M1 & T1) begin ctl_flags_nf_we=1; ctl_flags_nf_set=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; /* Clear CF going into the ALU core */ ctl_alu_sel_op2_neg=1; end if (M1 & T4) begin ctl_flags_nf_we=1; ctl_flags_nf_set=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; /* Clear CF going into the ALU core */ ctl_alu_sel_op2_neg=1; end end if ((M2 | M4) & pla[75]) begin begin ctl_flags_nf_we=1; ctl_flags_nf_set=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; /* Clear CF going into the ALU core */ ctl_alu_sel_op2_neg=1; end end if (use_ixiy & pla[53]) begin if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; nextM=1; end if (M3 & T1) begin ixy_d=1; /* Compute WZ=IX+d */ end if (M3 & T2) begin ixy_d=1; /* Compute WZ=IX+d */ end if (M3 & T3) begin ixy_d=1; /* Compute WZ=IX+d */ end if (M3 & T4) begin ixy_d=1; /* Compute WZ=IX+d */ end if (M3 & T5) begin nextM=1; ctl_mRead=1; ixy_d=1; /* Compute WZ=IX+d */ end end if (~use_ixiy & pla[53]) begin if (M1 & T2) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b01; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_oe=1; /* Enable FLAGT onto the data bus */ ctl_flags_hf_cpl=flags_nf; end if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1; /* Read 16-bit HL, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; end if (M2 & T3) begin fMRead=1; ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_zero=1; /* Zero */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_hf_we=1; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; ctl_flags_cf_set=1; /* Set CF going into the ALU core */ ctl_flags_cf2_we=1; end if (M2 & T4) begin nextM=1; ctl_mWrite=1; ctl_sw_2u=1; ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_pf_we=1; ctl_pf_sel=`PFSEL_V; ctl_flags_use_cf2=1; end if (M3 & T1) begin fMWrite=1; ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M3 & T2) begin fMWrite=1; end if (M3 & T3) begin fMWrite=1; setM1=1; end if (M4 & T1) begin fMRead=1; ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M4 & T2) begin fMRead=1; end if (M4 & T3) begin fMRead=1; ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_zero=1; /* Zero */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_hf_we=1; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; ctl_flags_cf_set=1; /* Set CF going into the ALU core */ ctl_flags_cf2_we=1; end if (M4 & T4) begin nextM=1; ctl_mWrite=1; ctl_sw_2u=1; ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_pf_we=1; ctl_pf_sel=`PFSEL_V; ctl_flags_use_cf2=1; end if (M5 & T1) begin fMWrite=1; ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M5 & T2) begin fMWrite=1; end if (M5 & T3) begin fMWrite=1; setM1=1; end end // 16-bit Arithmetic Group if (pla[69]) begin if (M1 & T2) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b01; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_oe=1; /* Enable FLAGT onto the data bus */ end if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; nextM=1; ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b01; ctl_reg_out_lo=1; /* From the register file onto the db1 (sw2 + FLAGT + sw1) */ ctl_sw_2d=1; ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op1_sel_bus=1; /* Internal bus */ end if (M2 & T1) begin ctl_reg_gp_sel=op54; ctl_reg_gp_hilo=2'b01; /* Read 8-bit GP register low byte */ ctl_reg_out_lo=1; /* From the register file onto the db1 (sw2 + FLAGT + sw1) */ ctl_sw_2d=1; ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_flags_cf_set|=ctl_alu_op_low; ctl_flags_cf_cpl|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_hf_we=1; ctl_reg_use_sp=1; /* For 16-bit loads: use SP instead of AF */ end if (M2 & T2) begin ctl_reg_sys_we_lo=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={ctl_reg_sys_hilo[1],1'b1}; /* Selecting only Z */ ctl_reg_in_lo=1; /* From the ALU side into the register file low byte only */ ctl_sw_2u=1; ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_xy_we=1; ctl_flags_cf_we=1; end if (M2 & T3) begin ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b10; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op1_sel_bus=1; /* Internal bus */ end if (M2 & T4) begin nextM=1; ctl_reg_gp_sel=op54; ctl_reg_gp_hilo=2'b10; /* Read 8-bit GP register high byte */ ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_hf_we=1; ctl_reg_use_sp=1; /* For 16-bit loads: use SP instead of AF */ end if (M3 & T1) begin ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1; /* Select 16-bit WZ */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_reg_sys_we_hi=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={1'b1,ctl_reg_sys_hilo[0]}; /* Selecting only W */ ctl_reg_in_hi=1; /* From the ALU side into the register file high byte only */ ctl_sw_2u=1; ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_xy_we=1; ctl_flags_cf_we=1; end if (M3 & T2) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b11; ctl_sw_4u=1; /* Write 16-bit HL, enable SW4 upstream */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M3 & T3) begin setM1=1; end end if (op3 & pla[68]) begin if (M1 & T2) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b01; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_oe=1; /* Enable FLAGT onto the data bus */ end if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; nextM=1; ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b01; ctl_reg_out_lo=1; /* From the register file onto the db1 (sw2 + FLAGT + sw1) */ ctl_sw_2d=1; ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op1_sel_bus=1; /* Internal bus */ end if (M2 & T1) begin ctl_reg_gp_sel=op54; ctl_reg_gp_hilo=2'b01; /* Read 8-bit GP register low byte */ ctl_reg_out_lo=1; /* From the register file onto the db1 (sw2 + FLAGT + sw1) */ ctl_sw_2d=1; ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_hf_we=1; ctl_reg_use_sp=1; /* For 16-bit loads: use SP instead of AF */ end if (M2 & T2) begin ctl_reg_sys_we_lo=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={ctl_reg_sys_hilo[1],1'b1}; /* Selecting only Z */ ctl_reg_in_lo=1; /* From the ALU side into the register file low byte only */ ctl_sw_2u=1; ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_cf_we=1; end if (M2 & T3) begin ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b10; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op1_sel_bus=1; /* Internal bus */ end if (M2 & T4) begin nextM=1; ctl_reg_gp_sel=op54; ctl_reg_gp_hilo=2'b10; /* Read 8-bit GP register high byte */ ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_hf_we=1; ctl_reg_use_sp=1; /* For 16-bit loads: use SP instead of AF */ end if (M3 & T1) begin ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1; /* Select 16-bit WZ */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_reg_sys_we_hi=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={1'b1,ctl_reg_sys_hilo[0]}; /* Selecting only W */ ctl_reg_in_hi=1; /* From the ALU side into the register file high byte only */ ctl_sw_2u=1; ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_pf_we=1; ctl_pf_sel=`PFSEL_V; ctl_flags_cf_we=1; ctl_alu_zero_16bit=1; /* 16-bit arithmetic operation uses ZF calculated over 2 bytes */ end if (M3 & T2) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b11; ctl_sw_4u=1; /* Write 16-bit HL, enable SW4 upstream */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M3 & T3) begin setM1=1; end end if (~op3 & pla[68]) begin if (M1 & T2) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b01; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_oe=1; /* Enable FLAGT onto the data bus */ ctl_flags_hf_cpl=flags_nf; ctl_flags_cf_cpl=flags_nf; end if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; ctl_flags_nf_set=1; ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; nextM=1; ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b01; ctl_reg_out_lo=1; /* From the register file onto the db1 (sw2 + FLAGT + sw1) */ ctl_sw_2d=1; ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op1_sel_bus=1; /* Internal bus */ end if (M2 & T1) begin ctl_reg_gp_sel=op54; ctl_reg_gp_hilo=2'b01; /* Read 8-bit GP register low byte */ ctl_reg_out_lo=1; /* From the register file onto the db1 (sw2 + FLAGT + sw1) */ ctl_sw_2d=1; ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_sel_op2_neg=1; ctl_flags_cf_cpl|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_hf_we=1; ctl_reg_use_sp=1; /* For 16-bit loads: use SP instead of AF */ end if (M2 & T2) begin ctl_reg_sys_we_lo=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={ctl_reg_sys_hilo[1],1'b1}; /* Selecting only Z */ ctl_reg_in_lo=1; /* From the ALU side into the register file low byte only */ ctl_sw_2u=1; ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_sel_op2_neg=1; ctl_flags_cf_cpl|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_cf_we=1; end if (M2 & T3) begin ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b10; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op1_sel_bus=1; /* Internal bus */ end if (M2 & T4) begin nextM=1; ctl_reg_gp_sel=op54; ctl_reg_gp_hilo=2'b10; /* Read 8-bit GP register high byte */ ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_sel_op2_neg=1; ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_hf_we=1; ctl_reg_use_sp=1; /* For 16-bit loads: use SP instead of AF */ end if (M3 & T1) begin ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1; /* Select 16-bit WZ */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_reg_sys_we_hi=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={1'b1,ctl_reg_sys_hilo[0]}; /* Selecting only W */ ctl_reg_in_hi=1; /* From the ALU side into the register file high byte only */ ctl_sw_2u=1; ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_sel_op2_neg=1; ctl_flags_cf_cpl|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_pf_we=1; ctl_pf_sel=`PFSEL_V; ctl_flags_cf_we=1; ctl_alu_zero_16bit=1; /* 16-bit arithmetic operation uses ZF calculated over 2 bytes */ end if (M3 & T2) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b11; ctl_sw_4u=1; /* Write 16-bit HL, enable SW4 upstream */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M3 & T3) begin setM1=1; end end if (pla[9]) begin if (M1 & T4) begin validPLA=1; ctl_reg_gp_sel=op54; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1; /* Read 16-bit general purpose register, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_reg_use_sp=1; /* For 16-bit loads: use SP instead of AF */ end if (M1 & T5) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=op54; ctl_reg_gp_hilo=2'b11; ctl_sw_4u=1; /* Write 16-bit general purpose register, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=op3; /* Decrement if op3 is set; increment otherwise */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ ctl_reg_use_sp=1; /* For 16-bit loads: use SP instead of AF */ end if (M1 & T6) begin setM1=1; end end // General Purpose Arithmetic and CPU Control Groups if (pla[77]) begin if (M1 & T1) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b10; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_pf_we=1; ctl_pf_sel=`PFSEL_P; ctl_flags_cf_we=1; ctl_alu_sel_op2_neg=flags_nf; ctl_flags_cf_cpl=~flags_nf; end if (M1 & T2) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b01; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_oe=1; /* Enable FLAGT onto the data bus */ ctl_flags_use_cf2=1; ctl_flags_hf_cpl=flags_nf; end if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf2_we=1; /* Write HF2 flag (DAA only) */ ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; setM1=1; ctl_sw_2d=1; ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_cf_set=1; /* Set CF going into the ALU core */ ctl_flags_cf2_we=1; ctl_flags_cf2_sel_daa=1; ctl_daa_oe=1; /* Write DAA correction factor to the bus */ ctl_alu_sel_op2_neg=flags_nf; ctl_flags_cf_cpl=~flags_nf; end end if (pla[81]) begin if (M1 & T1) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b10; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; ctl_flags_xy_we=1; ctl_flags_nf_we=1; ctl_flags_nf_set=1; ctl_alu_sel_op2_neg=1; end if (M1 & T2) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b01; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_oe=1; /* Enable FLAGT onto the data bus */ ctl_flags_hf_cpl=flags_nf; end if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; setM1=1; ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_op1_sel_zero=1; /* Zero */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_nf_we=1; ctl_flags_nf_set=1; ctl_alu_sel_op2_neg=1; end end if (pla[82]) begin if (M1 & T1) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b10; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_sel_op2_neg=1; ctl_flags_cf_set|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_pf_we=1; ctl_pf_sel=`PFSEL_V; ctl_flags_nf_we=1; ctl_flags_nf_set=1; ctl_flags_cf_we=1; end if (M1 & T2) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b01; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_oe=1; /* Enable FLAGT onto the data bus */ ctl_flags_hf_cpl=flags_nf; ctl_flags_cf_cpl=flags_nf; end if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; setM1=1; ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_op1_sel_zero=1; /* Zero */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_sel_op2_neg=1; ctl_flags_cf_set|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_nf_we=1; ctl_flags_nf_set=1; ctl_flags_cf_we=1; end end if (pla[89]) begin if (M1 & T1) begin ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; ctl_flags_xy_we=1; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; end if (M1 & T2) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b01; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_oe=1; /* Enable FLAGT onto the data bus */ ctl_flags_cf_we=1; ctl_flags_cf_cpl=1; /* CCF */ ctl_flags_hf_cpl=~flags_cf; /* Used for CCF */ end if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; setM1=1; ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; end end if (pla[92]) begin if (M1 & T1) begin ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; ctl_flags_xy_we=1; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; end if (M1 & T2) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b01; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_oe=1; /* Enable FLAGT onto the data bus */ ctl_flags_cf_set=1; /* Set CF going into the ALU core */ end if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; setM1=1; ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; end end if (pla[95]) begin if (M1 & T3) begin ctl_state_halt_set=1; /* Enter HALT state */ end if (M1 & T4) begin validPLA=1; setM1=1; end end if (pla[97]) begin if (M1 & T3) begin ctl_iffx_bit=op3; ctl_iffx_we=1; /* DI/EI */ end if (M1 & T4) begin validPLA=1; setM1=1; ctl_no_ints=1; /* Disable interrupt generation for this opcode (DI/EI/CB/ED/DD/FD) */ end end if (pla[96]) begin if (M1 & T3) begin ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_im_we=1; /* IM n ('n' is read by opcode[4:3]) */ end if (M1 & T4) begin validPLA=1; setM1=1; end end // Rotate and Shift Group if (pla[25]) begin if (M1 & T1) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b10; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; ctl_flags_cf_we=1; end if (M1 & T2) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b01; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_oe=1; /* Enable FLAGT onto the data bus */ ctl_flags_use_cf2=1; end if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; setM1=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b10; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=1; ctl_shift_en=1; /* Shifter unit AND shift enable! */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; ctl_flags_cf2_we=1; ctl_flags_cf2_sel_shift=1; end end if (~use_ixiy & pla[70] & ~pla[55]) begin if (M1 & T1) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=op21; ctl_reg_gp_hilo={~rsel0,rsel0}; /* Write 8-bit GP register selected by op[2:0] */ ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_sw_2u=1; ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_pf_sel=`PFSEL_P; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; ctl_flags_cf_we=1; end if (M1 & T2) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b01; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_oe=1; /* Enable FLAGT onto the data bus */ ctl_flags_use_cf2=1; end if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; setM1=1; ctl_reg_gp_sel=op21; ctl_reg_gp_hilo={~rsel0,rsel0};/* Read 8-bit GP register selected by op[2:0] */ ctl_reg_out_hi=~rsel0; ctl_reg_out_lo=rsel0; ctl_sw_2u=~rsel0; ctl_sw_2d=rsel0; /* Enable register gate based on the rsel0 */ /* Controlled by register gate */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=1; ctl_shift_en=1; /* Shifter unit AND shift enable! */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; ctl_flags_cf2_we=1; ctl_flags_cf2_sel_shift=1; end if (M4 & T1) begin fMRead=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1; /* Select 16-bit WZ */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_ir_we=1; end if (M4 & T2) begin fMRead=1; end if (M4 & T3) begin fMRead=1; nextM=1; ctl_mWrite=1; ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=1; ctl_shift_en=1; /* Shifter unit AND shift enable! */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; ctl_flags_cf2_we=1; ctl_flags_cf2_sel_shift=1; end if (M5 & T1) begin fMWrite=1; ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ ctl_sw_2u=1; ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_pf_sel=`PFSEL_P; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; ctl_flags_cf_we=1; end if (M5 & T2) begin fMWrite=1; end if (M5 & T3) begin fMWrite=1; setM1=1; end end if (~use_ixiy & pla[70] & pla[55]) begin if (M1 & T2) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b01; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_oe=1; /* Enable FLAGT onto the data bus */ ctl_flags_use_cf2=1; end if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1; /* Read 16-bit HL, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; end if (M2 & T3) begin fMRead=1; end if (M2 & T4) begin nextM=1; ctl_mWrite=1; ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=1; ctl_shift_en=1; /* Shifter unit AND shift enable! */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; ctl_flags_cf2_we=1; ctl_flags_cf2_sel_shift=1; end if (M3 & T1) begin fMWrite=1; ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ ctl_sw_2u=1; ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_pf_sel=`PFSEL_P; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; ctl_flags_cf_we=1; end if (M3 & T2) begin fMWrite=1; end if (M3 & T3) begin fMWrite=1; setM1=1; end if (M4 & T1) begin fMRead=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1; /* Select 16-bit WZ */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_ir_we=1; end if (M4 & T2) begin fMRead=1; end if (M4 & T3) begin fMRead=1; nextM=1; ctl_mWrite=1; ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=1; ctl_shift_en=1; /* Shifter unit AND shift enable! */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; ctl_flags_cf2_we=1; ctl_flags_cf2_sel_shift=1; end if (M5 & T1) begin fMWrite=1; ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ ctl_sw_2u=1; ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_pf_sel=`PFSEL_P; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; ctl_flags_cf_we=1; end if (M5 & T2) begin fMWrite=1; end if (M5 & T3) begin fMWrite=1; setM1=1; end end if (pla[15] & op3) begin if (M1 & T1) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b10; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_pf_we=1; ctl_pf_sel=`PFSEL_P; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; end if (M1 & T2) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b01; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_oe=1; /* Enable FLAGT onto the data bus */ end if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1; /* Read 16-bit HL, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4u=1; /* Write 16-bit WZ, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; nextM=1; end if (M3 & T1) begin ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_lq=1; /* Cross-bus wire (see schematic) */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ end if (M3 & T4) begin nextM=1; ctl_mWrite=1; ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op1_sel_low=1; /* Write low nibble with a high nibble */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ end if (M4 & T1) begin fMWrite=1; ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ ctl_sw_2u=1; ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_op2_oe=1; /* OP2 latch */ end if (M4 & T2) begin fMWrite=1; ctl_alu_op1_oe=1; /* OP1 latch */ ctl_alu_op2_sel_bus=1; /* Internal bus */ end if (M4 & T3) begin fMWrite=1; setM1=1; ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; end end if (pla[15] & ~op3) begin if (M1 & T1) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b10; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_pf_we=1; ctl_pf_sel=`PFSEL_P; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; end if (M1 & T2) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b01; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_oe=1; /* Enable FLAGT onto the data bus */ end if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1; /* Read 16-bit HL, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4u=1; /* Write 16-bit WZ, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; nextM=1; end if (M3 & T1) begin ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_lq=1; /* Cross-bus wire (see schematic) */ ctl_alu_op1_sel_low=1; /* Write low nibble with a high nibble */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ end if (M3 & T2) begin ctl_sw_2u=1; ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_op2_oe=1; /* OP2 latch */ end if (M3 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b10; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_lq=1; /* Cross-bus wire (see schematic) */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ end if (M3 & T4) begin nextM=1; ctl_mWrite=1; ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op1_sel_low=1; /* Write low nibble with a high nibble */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ end if (M4 & T1) begin fMWrite=1; ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ ctl_sw_2u=1; ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_op2_oe=1; /* OP2 latch */ end if (M4 & T2) begin fMWrite=1; ctl_alu_op1_oe=1; /* OP1 latch */ ctl_alu_op2_sel_bus=1; /* Internal bus */ end if (M4 & T3) begin fMWrite=1; setM1=1; ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; end end // Bit Manipulation Group if (~use_ixiy & pla[72] & ~pla[55]) begin if (M1 & T1) begin ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_sz_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_pf_sel=`PFSEL_P; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; end if (M1 & T2) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b01; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_oe=1; /* Enable FLAGT onto the data bus */ end if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_bs_oe=1; /* Bit-selector unit */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; setM1=1; ctl_reg_gp_sel=op21; ctl_reg_gp_hilo={~rsel0,rsel0};/* Read 8-bit GP register selected by op[2:0] */ ctl_reg_out_hi=~rsel0; ctl_reg_out_lo=rsel0; ctl_sw_2u=~rsel0; ctl_sw_2d=rsel0; /* Enable register gate based on the rsel0 */ /* Controlled by register gate */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; end if (M4 & T1) begin fMRead=1; ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_alu_bs_oe=1; /* Bit-selector unit */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_ir_we=1; end if (M4 & T2) begin fMRead=1; end if (M4 & T3) begin fMRead=1; end if (M4 & T4) begin setM1=1; ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_sz_we=1; ctl_flags_hf_we=1; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; end end if (~use_ixiy & pla[72] & pla[55]) begin if (M1 & T1) begin ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_sz_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_pf_sel=`PFSEL_P; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; end if (M1 & T2) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b01; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_oe=1; /* Enable FLAGT onto the data bus */ end if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_bs_oe=1; /* Bit-selector unit */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1; /* Read 16-bit HL, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; end if (M2 & T3) begin fMRead=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4u=1; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_flags_xy_we=1; end if (M2 & T4) begin setM1=1; ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_sz_we=1; ctl_flags_hf_we=1; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; end if (M4 & T1) begin fMRead=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1; /* Select 16-bit WZ */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_alu_bs_oe=1; /* Bit-selector unit */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_ir_we=1; end if (M4 & T2) begin fMRead=1; end if (M4 & T3) begin fMRead=1; end if (M4 & T4) begin setM1=1; ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_sz_we=1; ctl_flags_hf_we=1; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; end end if (~use_ixiy & pla[74] & ~pla[55]) begin if (M1 & T1) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=op21; ctl_reg_gp_hilo={~rsel0,rsel0}; /* Write 8-bit GP register selected by op[2:0] */ ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_sw_2u=1; ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; end if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_bs_oe=1; /* Bit-selector unit */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; setM1=1; ctl_reg_gp_sel=op21; ctl_reg_gp_hilo={~rsel0,rsel0};/* Read 8-bit GP register selected by op[2:0] */ ctl_reg_out_hi=~rsel0; ctl_reg_out_lo=rsel0; ctl_sw_2u=~rsel0; ctl_sw_2d=rsel0; /* Enable register gate based on the rsel0 */ /* Controlled by register gate */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; end if (M4 & T1) begin fMRead=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1; /* Select 16-bit WZ */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_alu_bs_oe=1; /* Bit-selector unit */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_ir_we=1; end if (M4 & T2) begin fMRead=1; end if (M4 & T3) begin fMRead=1; nextM=1; ctl_mWrite=1; ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; end if (M5 & T1) begin fMWrite=1; ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ ctl_sw_2u=1; ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; end if (M5 & T2) begin fMWrite=1; end if (M5 & T3) begin fMWrite=1; setM1=1; end end if (~use_ixiy & pla[74] & pla[55]) begin if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_bs_oe=1; /* Bit-selector unit */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1; /* Read 16-bit HL, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; end if (M2 & T3) begin fMRead=1; ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; end if (M2 & T4) begin nextM=1; ctl_mWrite=1; ctl_sw_2u=1; ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; end if (M3 & T1) begin fMWrite=1; ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M3 & T2) begin fMWrite=1; end if (M3 & T3) begin fMWrite=1; setM1=1; end if (M4 & T1) begin fMRead=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1; /* Select 16-bit WZ */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_alu_bs_oe=1; /* Bit-selector unit */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_ir_we=1; end if (M4 & T2) begin fMRead=1; end if (M4 & T3) begin fMRead=1; nextM=1; ctl_mWrite=1; ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; end if (M5 & T1) begin fMWrite=1; ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ ctl_sw_2u=1; ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; end if (M5 & T2) begin fMWrite=1; end if (M5 & T3) begin fMWrite=1; setM1=1; end end if (~use_ixiy & pla[73] & ~pla[55]) begin if (M1 & T1) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=op21; ctl_reg_gp_hilo={~rsel0,rsel0}; /* Write 8-bit GP register selected by op[2:0] */ ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_sw_2u=1; ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_alu_sel_op2_neg=1; end if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_bs_oe=1; /* Bit-selector unit */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; setM1=1; ctl_reg_gp_sel=op21; ctl_reg_gp_hilo={~rsel0,rsel0};/* Read 8-bit GP register selected by op[2:0] */ ctl_reg_out_hi=~rsel0; ctl_reg_out_lo=rsel0; ctl_sw_2u=~rsel0; ctl_sw_2d=rsel0; /* Enable register gate based on the rsel0 */ /* Controlled by register gate */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_alu_sel_op2_neg=1; end if (M4 & T1) begin fMRead=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1; /* Select 16-bit WZ */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_alu_bs_oe=1; /* Bit-selector unit */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_ir_we=1; end if (M4 & T2) begin fMRead=1; end if (M4 & T3) begin fMRead=1; nextM=1; ctl_mWrite=1; ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_alu_sel_op2_neg=1; end if (M5 & T1) begin fMWrite=1; ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ ctl_sw_2u=1; ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_alu_sel_op2_neg=1; end if (M5 & T2) begin fMWrite=1; end if (M5 & T3) begin fMWrite=1; setM1=1; end end if (~use_ixiy & pla[73] & pla[55]) begin if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_bs_oe=1; /* Bit-selector unit */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1; /* Read 16-bit HL, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; end if (M2 & T3) begin fMRead=1; ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_alu_sel_op2_neg=1; end if (M2 & T4) begin nextM=1; ctl_mWrite=1; ctl_sw_2u=1; ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_alu_sel_op2_neg=1; end if (M3 & T1) begin fMWrite=1; ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M3 & T2) begin fMWrite=1; end if (M3 & T3) begin fMWrite=1; setM1=1; end if (M4 & T1) begin fMRead=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1; /* Select 16-bit WZ */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_alu_bs_oe=1; /* Bit-selector unit */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_ir_we=1; end if (M4 & T2) begin fMRead=1; end if (M4 & T3) begin fMRead=1; nextM=1; ctl_mWrite=1; ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_alu_sel_op2_neg=1; end if (M5 & T1) begin fMWrite=1; ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ ctl_sw_2u=1; ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_alu_sel_op2_neg=1; end if (M5 & T2) begin fMWrite=1; end if (M5 & T3) begin fMWrite=1; setM1=1; end end // Input and Output Groups if (pla[37] & ~pla[28]) begin if (M1 & T1) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b10; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; nextM=1; ctl_iorw=1; end if (M3 & T1) begin fIORead=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b10; ctl_sw_4d=1; /* Read 8-bit general purpose A register, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ /* Which register to be written is decided elsewhere */ ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M3 & T2) begin fIORead=1; end if (M3 & T3) begin fIORead=1; end if (M3 & T4) begin fIORead=1; setM1=1; end end if (pla[27] & ~pla[34]) begin if (M1 & T1) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=op54; ctl_reg_gp_hilo={~rsel3,rsel3}; /* Write 8-bit GP register */ ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_pf_we=1; ctl_pf_sel=`PFSEL_P; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; end if (M1 & T2) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b01; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_oe=1; /* Enable FLAGT onto the data bus */ end if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; nextM=1; ctl_iorw=1; end if (M2 & T1) begin fIORead=1; ctl_reg_gp_sel=`GP_REG_BC; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1; /* Read 16-bit BC, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fIORead=1; end if (M2 & T3) begin fIORead=1; end if (M2 & T4) begin fIORead=1; setM1=1; ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; end end if (pla[37] & pla[28]) begin if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; nextM=1; ctl_iorw=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b10; ctl_sw_4d=1; /* Read 8-bit general purpose A register, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_reg_in_lo=1; /* From the ALU side into the register file low byte only */ ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M3 & T1) begin fIOWrite=1; ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b10; ctl_reg_out_hi=1; /* From the register file onto the db2 (sw2 + ALU) */ ctl_sw_2u=1; ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ end if (M3 & T2) begin fIOWrite=1; end if (M3 & T3) begin fIOWrite=1; end if (M3 & T4) begin fIOWrite=1; setM1=1; end end if (pla[27] & pla[34]) begin if (M1 & T4) begin validPLA=1; nextM=1; ctl_iorw=1; if (op4 & op5 & ~op3) begin ctl_bus_zero_oe=1; end /* Trying to read flags? Put 0 on the bus instead. */ if (~(op4 & op5 & ~op3)) begin ctl_reg_gp_sel=op54; ctl_reg_gp_hilo={~rsel3,rsel3}; end /* Read 8-bit GP register */ ctl_reg_out_hi=~rsel3; ctl_reg_out_lo=rsel3; ctl_sw_2u=~rsel3; ctl_sw_2d=rsel3; /* Enable register gate based on the rsel3 */ /* Controlled by register gate */ ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ end if (M2 & T1) begin fIOWrite=1; ctl_reg_gp_sel=`GP_REG_BC; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1; /* Read 16-bit BC, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fIOWrite=1; end if (M2 & T3) begin fIOWrite=1; end if (M2 & T4) begin fIOWrite=1; setM1=1; end end if (pla[91] & pla[21]) begin if (M1 & T1) begin ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_R=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; ctl_flags_pf_we=1; ctl_pf_sel=`PFSEL_P; end if (M1 & T2) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b01; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_oe=1; /* Enable FLAGT onto the data bus */ end if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; end if (M1 & T5) begin nextM=1; ctl_iorw=1; end if (M2 & T1) begin fIORead=1; ctl_reg_gp_sel=`GP_REG_BC; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1; /* Read 16-bit BC, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fIORead=1; ctl_reg_gp_sel=`GP_REG_BC; ctl_reg_gp_hilo=2'b10; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_zero=1; /* Zero */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_flags_cf_set|=ctl_alu_op_low; ctl_flags_cf_cpl|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_hf_we=1; ctl_alu_sel_op2_neg=1; end if (M2 & T3) begin fIORead=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_BC; ctl_reg_gp_hilo=2'b10; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_flags_cf_set|=ctl_alu_op_low; ctl_flags_cf_cpl|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_cf_we=1; ctl_alu_sel_op2_neg=1; end if (M2 & T4) begin fIORead=1; nextM=1; ctl_mWrite=1; ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_nf_we=1; /* Sign bit, to be used with FLAGT source set to "alu" */ ctl_alu_sel_op2_neg=1; end if (M3 & T1) begin fMWrite=1; ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1; /* Read 16-bit HL, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M3 & T2) begin fMWrite=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b11; ctl_sw_4u=1; /* Write 16-bit HL, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=op3; /* Decrement if op3 is set; increment otherwise */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M3 & T3) begin fMWrite=1; nextM=1; setM1=nonRep | flags_zf; end if (M4 & T1) begin ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M4 & T2) begin ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M4 & T3) begin ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M4 & T4) begin ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M4 & T5) begin setM1=1; end end if (pla[91] & pla[20]) begin if (M1 & T1) begin ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_R=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; ctl_flags_pf_we=1; ctl_pf_sel=`PFSEL_P; end if (M1 & T2) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b01; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_oe=1; /* Enable FLAGT onto the data bus */ end if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; ctl_reg_gp_sel=`GP_REG_BC; ctl_reg_gp_hilo=2'b10; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_zero=1; /* Zero */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_flags_cf_set|=ctl_alu_op_low; ctl_flags_cf_cpl|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_hf_we=1; ctl_alu_sel_op2_neg=1; end if (M1 & T5) begin nextM=1; ctl_mRead=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_BC; ctl_reg_gp_hilo=2'b10; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_flags_cf_set|=ctl_alu_op_low; ctl_flags_cf_cpl|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_alu_sel_op2_neg=1; end if (M2 & T1) begin fMRead=1; ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1; /* Read 16-bit HL, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b11; ctl_sw_4u=1; /* Write 16-bit HL, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=op3; /* Decrement if op3 is set; increment otherwise */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; nextM=1; ctl_iorw=1; ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b01; ctl_reg_out_lo=1; /* From the register file onto the db1 (sw2 + FLAGT + sw1) */ ctl_sw_2d=1; ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op1_sel_bus=1; /* Internal bus */ end if (M3 & T1) begin fIOWrite=1; ctl_reg_gp_sel=`GP_REG_BC; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1; /* Read 16-bit BC, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M3 & T2) begin fIOWrite=1; ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_flags_cf_set|=ctl_alu_op_low; ctl_flags_cf_cpl|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_hf_we=1; ctl_flags_nf_we=1; /* Sign bit, to be used with FLAGT source set to "alu" */ end if (M3 & T3) begin fIOWrite=1; ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_flags_cf_set|=ctl_alu_op_low; ctl_flags_cf_cpl|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_cf_we=1; end if (M3 & T4) begin fIOWrite=1; nextM=1; setM1=nonRep | flags_zf; end if (M4 & T1) begin ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M4 & T2) begin ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M4 & T3) begin ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M4 & T4) begin ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M4 & T5) begin setM1=1; end end // Jump Group if (pla[29]) begin if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; nextM=1; ctl_mRead=1; ctl_reg_sys_we_lo=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={ctl_reg_sys_hilo[1],1'b1}; /* Selecting only Z */ ctl_reg_in_lo=1; /* From the ALU side into the register file low byte only */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M3 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M3 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M3 & T3) begin fMRead=1; setM1=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1; /* Select 16-bit WZ */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_reg_sys_we_hi=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={1'b1,ctl_reg_sys_hilo[0]}; /* Selecting only W */ ctl_reg_in_hi=1; /* From the ALU side into the register file high byte only */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_reg_not_pc=1; /* For M1/T1 load from a register other than PC */ end end if (pla[43]) begin if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; nextM=1; ctl_mRead=1; ctl_reg_sys_we_lo=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={ctl_reg_sys_hilo[1],1'b1}; /* Selecting only Z */ ctl_reg_in_lo=1; /* From the ALU side into the register file low byte only */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M3 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M3 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M3 & T3) begin fMRead=1; setM1=1; ctl_reg_not_pc|=flags_cond_true; ctl_reg_sel_wz|=flags_cond_true; ctl_reg_sys_hilo|={flags_cond_true,flags_cond_true}; ctl_sw_4d|=flags_cond_true; ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_reg_sys_we_hi=flags_cond_true; ctl_reg_sel_wz=flags_cond_true; ctl_reg_sys_hilo={1'b1,ctl_reg_sys_hilo[0]}; /* Conditionally selecting only W */ ctl_reg_in_hi=1; /* From the ALU side into the register file high byte only */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end end if (pla[47]) begin if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; nextM=1; end if (M3 & T1) begin ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; end if (M3 & T2) begin ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b01; ctl_sw_4u=1; ctl_reg_out_lo=1; /* From the register file onto the db1 (sw2 + FLAGT + sw1) */ ctl_sw_2d=1; ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_flags_cf_set|=ctl_alu_op_low; ctl_flags_cf_cpl|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_hf_we=1; end if (M3 & T3) begin ctl_reg_sys_we_lo=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={ctl_reg_sys_hilo[1],1'b1}; /* Selecting only Z */ ctl_reg_in_lo=1; /* From the ALU side into the register file low byte only */ ctl_sw_2u=1; ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_flags_cf_set|=ctl_alu_op_low; ctl_flags_cf_cpl|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_cf_we=1; end if (M3 & T4) begin ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b10; ctl_sw_4u=1; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_zero=1; /* Zero */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_hf_we=1; ctl_alu_sel_op2_neg=flags_sf; end if (M3 & T5) begin setM1=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1; /* Select 16-bit WZ */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_reg_sys_we_hi=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={1'b1,ctl_reg_sys_hilo[0]}; /* Selecting only W */ ctl_reg_in_hi=1; /* From the ALU side into the register file high byte only */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_hf|=~ctl_alu_op_low; ctl_alu_sel_op2_neg=flags_sf; ctl_reg_not_pc=1; /* For M1/T1 load from a register other than PC */ end end if (pla[48]) begin if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; ctl_cond_short=1; /* M1/T3 only: force a short flags condition (SS) */ end if (M2 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; nextM=1; setM1=~flags_cond_true; end if (M3 & T1) begin ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; end if (M3 & T2) begin ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b01; ctl_sw_4u=1; ctl_reg_out_lo=1; /* From the register file onto the db1 (sw2 + FLAGT + sw1) */ ctl_sw_2d=1; ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_flags_cf_set|=ctl_alu_op_low; ctl_flags_cf_cpl|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_hf_we=1; end if (M3 & T3) begin ctl_reg_sys_we_lo=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={ctl_reg_sys_hilo[1],1'b1}; /* Selecting only Z */ ctl_reg_in_lo=1; /* From the ALU side into the register file low byte only */ ctl_sw_2u=1; ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_flags_cf_set|=ctl_alu_op_low; ctl_flags_cf_cpl|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_cf_we=1; end if (M3 & T4) begin ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b10; ctl_sw_4u=1; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_zero=1; /* Zero */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_hf_we=1; ctl_alu_sel_op2_neg=flags_sf; end if (M3 & T5) begin setM1=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1; /* Select 16-bit WZ */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_reg_sys_we_hi=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={1'b1,ctl_reg_sys_hilo[0]}; /* Selecting only W */ ctl_reg_in_hi=1; /* From the ALU side into the register file high byte only */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_hf|=~ctl_alu_op_low; ctl_alu_sel_op2_neg=flags_sf; ctl_reg_not_pc=1; /* For M1/T1 load from a register other than PC */ end end if (pla[6]) begin if (M1 & T4) begin validPLA=1; setM1=1; ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1; /* Read 16-bit HL, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_reg_not_pc=1; /* For M1/T1 load from a register other than PC */ end end if (pla[26]) begin if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; ctl_reg_gp_sel=`GP_REG_BC; ctl_reg_gp_hilo=2'b10; ctl_reg_out_hi=1; /* From the register file onto the db2 (sw2 + ALU) */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_zero=1; /* Zero */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_flags_cf_set|=ctl_alu_op_low; ctl_flags_cf_cpl|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_hf_we=1; ctl_alu_sel_op2_neg=1; end if (M1 & T5) begin nextM=1; ctl_mRead=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_BC; ctl_reg_gp_hilo=2'b10; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_flags_cf_set|=ctl_alu_op_low; ctl_flags_cf_cpl|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_sz_we=1; ctl_alu_sel_op2_neg=1; end if (M2 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; nextM=1; setM1=flags_zf; /* Used in DJNZ */ end if (M3 & T1) begin ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; end if (M3 & T2) begin ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b01; ctl_sw_4u=1; ctl_reg_out_lo=1; /* From the register file onto the db1 (sw2 + FLAGT + sw1) */ ctl_sw_2d=1; ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_flags_cf_set|=ctl_alu_op_low; ctl_flags_cf_cpl|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_hf_we=1; end if (M3 & T3) begin ctl_reg_sys_we_lo=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={ctl_reg_sys_hilo[1],1'b1}; /* Selecting only Z */ ctl_reg_in_lo=1; /* From the ALU side into the register file low byte only */ ctl_sw_2u=1; ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_flags_cf_set|=ctl_alu_op_low; ctl_flags_cf_cpl|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_cf_we=1; end if (M3 & T4) begin ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b10; ctl_sw_4u=1; ctl_reg_out_hi=1; /* From the register file onto the db2 (sw2 + ALU) */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_zero=1; /* Zero */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_hf_we=1; ctl_alu_sel_op2_neg=flags_sf; end if (M3 & T5) begin setM1=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1; /* Select 16-bit WZ */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_reg_sys_we_hi=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={1'b1,ctl_reg_sys_hilo[0]}; /* Selecting only W */ ctl_reg_in_hi=1; /* From the ALU side into the register file high byte only */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_hf|=~ctl_alu_op_low; ctl_alu_sel_op2_neg=flags_sf; ctl_reg_not_pc=1; /* For M1/T1 load from a register other than PC */ end end // Call and Return Group if (pla[24]) begin if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; nextM=1; ctl_mRead=1; ctl_reg_sys_we_lo=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={ctl_reg_sys_hilo[1],1'b1}; /* Selecting only Z */ ctl_reg_in_lo=1; /* From the ALU side into the register file low byte only */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M3 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M3 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M3 & T3) begin fMRead=1; ctl_reg_sys_we_hi=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={1'b1,ctl_reg_sys_hilo[0]}; /* Selecting only W */ ctl_reg_in_hi=1; /* From the ALU side into the register file high byte only */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M3 & T4) begin nextM=1; ctl_mWrite=1; ctl_reg_use_sp=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1;/* Read 16-bit SP, enable SW4 downstream */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M4 & T1) begin fMWrite=1; ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_apin_mux=1; /* Apin sourced from incrementer */ ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b10; ctl_sw_4u=1; ctl_reg_out_hi=1; /* From the register file onto the db2 (sw2 + ALU) */ ctl_sw_2u=1; ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ end if (M4 & T2) begin fMWrite=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_use_sp=1; ctl_sw_4u=1; /* Write 16-bit SP, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M4 & T3) begin fMWrite=1; nextM=1; ctl_mWrite=1; ctl_reg_use_sp=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1;/* Read 16-bit SP, enable SW4 downstream */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M5 & T1) begin fMWrite=1; ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_apin_mux=1; /* Apin sourced from incrementer */ ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b01; ctl_sw_4u=1; ctl_reg_out_lo=1; /* From the register file onto the db1 (sw2 + FLAGT + sw1) */ ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ end if (M5 & T2) begin fMWrite=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_use_sp=1; ctl_sw_4u=1; /* Write 16-bit SP, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M5 & T3) begin fMWrite=1; setM1=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1; /* Select 16-bit WZ */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_reg_not_pc=1; /* For M1/T1 load from a register other than PC */ end end if (pla[42]) begin if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; nextM=1; ctl_mRead=1; ctl_reg_sys_we_lo=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={ctl_reg_sys_hilo[1],1'b1}; /* Selecting only Z */ ctl_reg_in_lo=1; /* From the ALU side into the register file low byte only */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M3 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M3 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M3 & T3) begin fMRead=1; nextM=~flags_cond_true; setM1=~flags_cond_true; ctl_reg_sys_we_hi=flags_cond_true; ctl_reg_sel_wz=flags_cond_true; ctl_reg_sys_hilo={1'b1,ctl_reg_sys_hilo[0]}; /* Conditionally selecting only W */ ctl_reg_in_hi=1; /* From the ALU side into the register file high byte only */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M3 & T4) begin nextM=1; ctl_mWrite=1; ctl_reg_use_sp=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1;/* Read 16-bit SP, enable SW4 downstream */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M4 & T1) begin fMWrite=1; ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_apin_mux=1; /* Apin sourced from incrementer */ ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b10; ctl_sw_4u=1; ctl_reg_out_hi=1; /* From the register file onto the db2 (sw2 + ALU) */ ctl_sw_2u=1; ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ end if (M4 & T2) begin fMWrite=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_use_sp=1; ctl_sw_4u=1; /* Write 16-bit SP, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M4 & T3) begin fMWrite=1; nextM=1; ctl_mWrite=1; ctl_reg_use_sp=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1;/* Read 16-bit SP, enable SW4 downstream */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M5 & T1) begin fMWrite=1; ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_apin_mux=1; /* Apin sourced from incrementer */ ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b01; ctl_sw_4u=1; ctl_reg_out_lo=1; /* From the register file onto the db1 (sw2 + FLAGT + sw1) */ ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ end if (M5 & T2) begin fMWrite=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_use_sp=1; ctl_sw_4u=1; /* Write 16-bit SP, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M5 & T3) begin fMWrite=1; setM1=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1; /* Select 16-bit WZ */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_reg_not_pc=1; /* For M1/T1 load from a register other than PC */ end end if (pla[35]) begin if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_use_sp=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1;/* Read 16-bit SP, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_use_sp=1; ctl_sw_4u=1; /* Write 16-bit SP, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; nextM=1; ctl_mRead=1; ctl_reg_sys_we_lo=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={ctl_reg_sys_hilo[1],1'b1}; /* Selecting only Z */ ctl_reg_in_lo=1; /* From the ALU side into the register file low byte only */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M3 & T1) begin fMRead=1; ctl_reg_use_sp=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1;/* Read 16-bit SP, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M3 & T2) begin fMRead=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_use_sp=1; ctl_sw_4u=1; /* Write 16-bit SP, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M3 & T3) begin fMRead=1; setM1=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1; /* Select 16-bit WZ */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_reg_sys_we_hi=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={1'b1,ctl_reg_sys_hilo[0]}; /* Selecting only W */ ctl_reg_in_hi=1; /* From the ALU side into the register file high byte only */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_reg_not_pc=1; /* For M1/T1 load from a register other than PC */ end end if (pla[45]) begin if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; end if (M1 & T4) begin validPLA=1; end if (M1 & T5) begin nextM=1; ctl_mRead=1; setM1=~flags_cond_true; end if (M2 & T1) begin fMRead=1; ctl_reg_use_sp=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1;/* Read 16-bit SP, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_use_sp=1; ctl_sw_4u=1; /* Write 16-bit SP, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; nextM=1; ctl_mRead=1; ctl_reg_sys_we_lo=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={ctl_reg_sys_hilo[1],1'b1}; /* Selecting only Z */ ctl_reg_in_lo=1; /* From the ALU side into the register file low byte only */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M3 & T1) begin fMRead=1; ctl_reg_use_sp=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1;/* Read 16-bit SP, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M3 & T2) begin fMRead=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_use_sp=1; ctl_sw_4u=1; /* Write 16-bit SP, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M3 & T3) begin fMRead=1; setM1=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1; /* Select 16-bit WZ */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_reg_sys_we_hi=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={1'b1,ctl_reg_sys_hilo[0]}; /* Selecting only W */ ctl_reg_in_hi=1; /* From the ALU side into the register file high byte only */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_reg_not_pc=1; /* For M1/T1 load from a register other than PC */ end end if (pla[46]) begin if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; ctl_iff1_iff2=1; /* RETN copies IFF2 into IFF1 */ end if (M2 & T1) begin fMRead=1; ctl_reg_use_sp=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1;/* Read 16-bit SP, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_use_sp=1; ctl_sw_4u=1; /* Write 16-bit SP, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; nextM=1; ctl_mRead=1; ctl_reg_sys_we_lo=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={ctl_reg_sys_hilo[1],1'b1}; /* Selecting only Z */ ctl_reg_in_lo=1; /* From the ALU side into the register file low byte only */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M3 & T1) begin fMRead=1; ctl_reg_use_sp=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1;/* Read 16-bit SP, enable SW4 downstream */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M3 & T2) begin fMRead=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_use_sp=1; ctl_sw_4u=1; /* Write 16-bit SP, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M3 & T3) begin fMRead=1; setM1=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1; /* Select 16-bit WZ */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_reg_sys_we_hi=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={1'b1,ctl_reg_sys_hilo[0]}; /* Selecting only W */ ctl_reg_in_hi=1; /* From the ALU side into the register file high byte only */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_reg_not_pc=1; /* For M1/T1 load from a register other than PC */ end end if (pla[56]) begin if (M1 & T3) begin ctl_reg_sys_we=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_op1_oe=1; /* OP1 latch */ ctl_alu_op1_sel_zero=1; /* Zero */ ctl_sw_mask543_en=~((in_intr & im2) | in_nmi); ctl_sw_1d=~in_nmi; ctl_66_oe=in_nmi; ctl_bus_ff_oe=in_intr & im1; end if (M1 & T4) begin validPLA=1; end if (M1 & T5) begin nextM=1; ctl_mWrite=1; ctl_reg_use_sp=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1;/* Read 16-bit SP, enable SW4 downstream */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op1_sel_bus=1; /* Internal bus */ end if (M2 & T1) begin fMWrite=1; ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_apin_mux=1; /* Apin sourced from incrementer */ ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b10; ctl_sw_4u=1; ctl_reg_out_hi=1; /* From the register file onto the db2 (sw2 + ALU) */ ctl_sw_2u=1; ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ end if (M2 & T2) begin fMWrite=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_use_sp=1; ctl_sw_4u=1; /* Write 16-bit SP, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMWrite=1; nextM=1; ctl_mWrite=1; ctl_reg_use_sp=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1;/* Read 16-bit SP, enable SW4 downstream */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M3 & T1) begin fMWrite=1; ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_apin_mux=1; /* Apin sourced from incrementer */ ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b01; ctl_sw_4u=1; ctl_reg_out_lo=1; /* From the register file onto the db1 (sw2 + FLAGT + sw1) */ ctl_sw_1u=1; ctl_bus_db_we=1; /* Write DB pads with internal data bus value */ end if (M3 & T2) begin fMWrite=1; ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_use_sp=1; ctl_sw_4u=1; /* Write 16-bit SP, enable SW4 upstream */ ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1; /* Decrement */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M3 & T3) begin fMWrite=1; nextM=1; ctl_mRead=in_intr & im2; /* RST38 interrupt extension */ setM1=~(in_intr & im2); /* RST38 interrupt extension */ ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1; /* Select 16-bit WZ */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_reg_not_pc=1; /* For M1/T1 load from a register other than PC */ end // INTR IM2 continues here... if (M4 & T1) begin fMRead=1; ctl_reg_sel_ir=1; ctl_reg_sys_hilo=2'b10; ctl_sw_4d=1; /* Select 8-bit I register */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_reg_in_lo=1; /* From the ALU side into the register file low byte only */ ctl_sw_2u=1; ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_op1_oe=1; /* OP1 latch */ end if (M4 & T2) begin fMRead=1; ctl_sw_4u=1; ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ ctl_reg_out_lo=1; /* From the register file onto the db1 (sw2 + FLAGT + sw1) */ ctl_sw_2d=1; ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op1_sel_bus=1; /* Internal bus */ end if (M4 & T3) begin fMRead=1; nextM=1; ctl_mRead=1; ctl_reg_sys_we_lo=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={ctl_reg_sys_hilo[1],1'b1}; /* Selecting only Z */ ctl_reg_in_lo=1; /* From the ALU side into the register file low byte only */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ end if (M5 & T1) begin fMRead=1; ctl_reg_sel_ir=1; ctl_reg_sys_hilo=2'b10; ctl_sw_4d=1; /* Select 8-bit I register */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_reg_in_lo=1; /* From the ALU side into the register file low byte only */ ctl_sw_2u=1; ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_op1_oe=1; /* OP1 latch */ end if (M5 & T2) begin fMRead=1; ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M5 & T3) begin fMRead=1; setM1=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1; /* Select 16-bit WZ */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_reg_sys_we_hi=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={1'b1,ctl_reg_sys_hilo[0]}; /* Selecting only W */ ctl_reg_in_hi=1; /* From the ALU side into the register file high byte only */ ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_reg_not_pc=1; /* For M1/T1 load from a register other than PC */ end end // CB-Table opcodes if (pla[49]) begin if (M1 & T3) begin ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_bus=1; /* Load FLAGT from the data bus */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; ctl_flags_xy_we=1; ctl_flags_hf_we=1; ctl_flags_pf_we=1; ctl_flags_nf_we=1; /* Previous NF, to be used when loading FLAGT */ ctl_flags_cf_we=1; ctl_state_tbl_we=1; ctl_state_tbl_cb_set=1; /* CB-table prefix */ end if (M1 & T4) begin validPLA=1; nextM=1; ctl_mRead=1; end if (M2 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end if (M2 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ end if (M2 & T3) begin fMRead=1; nextM=1; ctl_mRead=1; end if (M3 & T1) begin fMRead=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ixy_d=1; /* Compute WZ=IX+d */ end if (M3 & T2) begin fMRead=1; ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; /* Output enable incrementer to the register bus */ ixy_d=1; /* Compute WZ=IX+d */ end if (M3 & T3) begin fMRead=1; ixy_d=1; /* Compute WZ=IX+d */ end if (M3 & T4) begin ixy_d=1; /* Compute WZ=IX+d */ end if (M3 & T5) begin nextM=1; ctl_mRead=1; ixy_d=1; /* Compute WZ=IX+d */ end if (M4 & T1) begin ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_alu_bs_oe=1; /* Bit-selector unit */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_ir_we=1; end // Loading a new instruction immediately changes PLA wires and continues into the new effective instructions' M4/T1 cycle end // Special Purposes PLA Entries if (pla[3]) begin if (M1 & T2) begin ctl_state_ixiy_we=1; ctl_state_iy_set=op5; setIXIY=1; /* IX/IY prefix */ end if (M1 & T4) begin validPLA=1; setM1=1; ctl_no_ints=1; /* Disable interrupt generation for this opcode (DI/EI/CB/ED/DD/FD) */ end end if (pla[44]) begin if (M1 & T2) begin ctl_state_tbl_we=1; ctl_state_tbl_cb_set=1; /* CB-table prefix */ end if (M1 & T4) begin validPLA=1; setM1=1; ctl_no_ints=1; /* Disable interrupt generation for this opcode (DI/EI/CB/ED/DD/FD) */ end end if (pla[51]) begin if (M1 & T2) begin ctl_state_tbl_we=1; ctl_state_tbl_ed_set=1; /* ED-table prefix */ end if (M1 & T4) begin validPLA=1; setM1=1; ctl_no_ints=1; /* Disable interrupt generation for this opcode (DI/EI/CB/ED/DD/FD) */ end end if (pla[76]) begin begin ctl_alu_sel_op2_neg=1; ctl_flags_cf_set|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_nf_we=1; ctl_flags_nf_set=1; end if (M1 & T1) begin ctl_flags_pf_we=1; ctl_pf_sel=`PFSEL_V; end end if (pla[78]) begin begin ctl_alu_sel_op2_neg=1; ctl_flags_cf_set|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_nf_we=1; ctl_flags_nf_set=1; end if (M1 & T1) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b10; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_xy_we=1; ctl_flags_pf_we=1; ctl_pf_sel=`PFSEL_V; end end if (pla[79]) begin begin ctl_alu_sel_op2_neg=1; ctl_flags_cf_cpl|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_nf_we=1; ctl_flags_nf_set=1; end if (M1 & T1) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b10; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_xy_we=1; ctl_flags_pf_we=1; ctl_pf_sel=`PFSEL_V; end end if (pla[80]) begin begin ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; end if (M1 & T1) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b10; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_xy_we=1; ctl_flags_pf_we=1; ctl_pf_sel=`PFSEL_V; end end if (pla[84]) begin begin ctl_flags_cf_set|=ctl_alu_op_low; ctl_flags_cf_cpl|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; end if (M1 & T1) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b10; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_xy_we=1; ctl_flags_pf_we=1; ctl_pf_sel=`PFSEL_V; end end if (pla[85]) begin begin ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; end if (M1 & T1) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b10; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_xy_we=1; ctl_flags_pf_we=1; ctl_pf_sel=`PFSEL_P; end if (M1 & T2) begin ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; /* Clear CF going into the ALU core */ end end if (pla[86]) begin begin ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; end if (M1 & T1) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b10; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_xy_we=1; ctl_flags_pf_we=1; ctl_pf_sel=`PFSEL_P; end if (M1 & T2) begin ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; /* Clear CF going into the ALU core */ end end if (pla[88]) begin begin ctl_alu_core_R=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; ctl_flags_nf_we=1; ctl_flags_nf_clr=1; end if (M1 & T1) begin ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b10; ctl_reg_in_hi=1; ctl_reg_in_lo=1; /* From the ALU side into the register file */ ctl_flags_xy_we=1; ctl_flags_pf_we=1; ctl_pf_sel=`PFSEL_P; end if (M1 & T2) begin ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; /* Clear CF going into the ALU core */ end end // State machine to compute (IX+d) if (ixy_d) begin if (T1) begin ctl_sw_2d=1; ctl_sw_1d=1; ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_bus=1; /* Internal bus */ ctl_flags_sz_we=1; end if (T2) begin ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b01; ctl_reg_out_lo=1; /* From the register file onto the db1 (sw2 + FLAGT + sw1) */ ctl_sw_2d=1; ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_flags_cf_set|=ctl_alu_op_low; ctl_flags_cf_cpl|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_hf_we=1; end if (T3) begin ctl_reg_sys_we_lo=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={ctl_reg_sys_hilo[1],1'b1}; /* Selecting only Z */ ctl_reg_in_lo=1; /* From the ALU side into the register file low byte only */ ctl_sw_2u=1; ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_cf2_we=1; end if (T4) begin ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b10; ctl_reg_out_hi=1; ctl_reg_out_lo=1; /* From the register file into the FLAGT and ALU */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_shift_oe=~ctl_alu_bs_oe; /* Shifter unit without shift-enable */ ctl_alu_op2_sel_zero=1; /* Zero */ ctl_alu_op1_sel_bus=1; /* Internal bus */ ctl_alu_op_low=1; /* Activate ALU operation on low nibble */ ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_hf_we=1; ctl_flags_use_cf2=1; ctl_alu_sel_op2_neg=flags_sf; end if (T5) begin ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1; /* Select 16-bit WZ */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_reg_sys_we_hi=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={1'b1,ctl_reg_sys_hilo[0]}; /* Selecting only W */ ctl_reg_in_hi=1; /* From the ALU side into the register file high byte only */ ctl_flags_alu=1; /* Load FLAGT from the ALU */ ctl_alu_oe=1; /* Enable ALU onto the data bus */ ctl_alu_res_oe=1; /* Result latch */ ctl_alu_sel_op2_high=1; /* Activate ALU operation on high nibble */ ctl_alu_core_hf|=~ctl_alu_op_low; ctl_flags_xy_we=1; ctl_alu_sel_op2_neg=flags_sf; ctl_state_ixiy_we=1; ctl_state_ixiy_clr=~setIXIY; /* Clear IX/IY flag if not explicitly set */ end end // Default instruction fetch (M1) state machine if (1) begin if (M1 & T1) begin ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); /* Write 16-bit PC and control incrementer */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; ctl_apin_mux2=1; /* Apin sourced from AL */ end if (M1 & T2) begin ctl_reg_sel_ir=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit IR */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ ctl_bus_db_oe=1; /* Read DB pads to internal data bus */ ctl_state_ixiy_we=1; ctl_state_ixiy_clr=~setIXIY; /* Clear IX/IY flag if not explicitly set */ ctl_state_tbl_we=1; /* Clear CB/ED prefix if not explicitly set */ ctl_ir_we=1; ctl_bus_zero_oe=in_halt; ctl_bus_ff_oe=(in_intr & (im1 | im2)) | in_nmi; end if (M1 & T3) begin ctl_reg_sys_we=1; ctl_reg_sel_ir=1; ctl_reg_sys_hilo=2'b11; /* Write 16-bit IR */ ctl_inc_cy=~pc_inc_hold; /* Increment */ ctl_bus_inc_oe=1; ctl_apin_mux2=1; /* Apin sourced from AL */ ctl_inc_limit6=1; /* Limit the incrementer to 6 bits */ end if (M1 & T4) begin ctl_eval_cond=1; /* Evaluate flags condition based on the opcode[5:3] */ end end // For all undecoded instructions, at M1/T4 advance a byte to the next opcode if (~validPLA) begin if (M1 & T4) begin setM1=1; end end // The last cycle of an instruction is also the first cycle of the next one if (setM1) begin begin ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; /* Select 16-bit PC */ ctl_al_we=1; /* Write a value from the register bus to the address latch */ end end