This is a list of some hard-to-find publications on the Z80 CPU.
Month: September 2014
A Z80 : References
This design would not be possible without Ken Shirriff who reverse-engineered some major portions of Z80 from the picture of a die. These are the portions of the A-Z80 design that are based on his work:
Continue readingA Z80 : The Soul
In the first post, I described the sequencer, a circuit that provided discrete timing signals to space operations apart. In the second post, I mentioned the Timing matrix that was run by these signals and orchestrated the dance of control signals in time.
This article is about making it all alive and kicking within an FPGA solution.
A Z80 : The Mind
In the last article, I described the sequencer, which is the heart of a CPU, and a few other blocks that perform various tasks. But how is it all orchestrated to perform useful work?
Enter the PLA and the Timing matrix – the mind of a CPU.
A Z80 : The Heart
Click on any image to open a higher-resolution version.
This is how it all works.
The sequencer is “the heart” of a CPU. It gets the external clock which in turn toggles two rows of flip-flops that generate machine cycles (M-cycles) and clock periods (T-states).
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A Z80 From the Ground Up
A-Z80 is a conceptual implementation of the venerable Zilog Z80 processor targeted to synthesize and run on a modern FPGA device. It differs from the existing (mostly Verilog) Z80 implementations in that it is designed from the ground up through the schematics and low-level gates.
