cpld-cpu

Imported from GitHub: jimmo/cpld-cpu · commit 000aafa · license MIT

Description

A simple CPU implemented by discrete CPLD components.

README

This exactly implements the CPU from https://github.com/cpldcpu/MCPU

The implementation here is written to match the original VHDL as closely as possible. It's almost line for line identical other than syntax changes to match pysim.

I've added an assembler that generates the same machine code, including the macro ops described such as sub, etc plus a few more. Additionally, the assembler automatically generates some useful constant values at known locations, such as one, allones, etc, and a simple memory-mapped output interface.

There are three demos:

• tests/count.s -- demonstrates counting up and down with output
• tests/mem.s -- uses self-modifying code to fill RAM with a sequence
• tests/prime.s -- copied from https://jeelabs.org/2017/11/tfoc---a-minimal-computer/