hm-51 Documention

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Table of Cotents

• Introduction
• Project Structure
• Check The Degin Before Anything

Introduction

hm-51 is a digital circuit project about 8051 CPU. The ultimate goal of hm-51 is to use common logic chip to build a CPU that supports MSC-51 ISA. I focus on two targets:

• Support All MSC-51, which means we can write programs in C without worrying about which instructions we did not implement.

• Keeping the hardware design on a smaller scale, which means that if we want to implement it using real commercially available DIP digital logic chips, we will not get a giant circuit.

In fact, we only care about the correct behavior of the instructions. I have never considered it to be consistent with the standard hardware behavior. I also discarded many non-essential SFRs to keep the circuit compact. Therefore, before starting any software work, you should read the summary [Don't assume what hardware doing] in README-circ.md.

The hardware design is hignly perosnalized, you can check the file README-hd.md if you are interasted in my work.

Project Structure

• src
  • alu: contain program to generate ALU LUT's binary file, see README.md.
  • circuit: contain all circuit design file
    • CORE.dig: main entry of circuit design.
  • decoder: contain all decoder script that describe deocder's LUT.
    • decoder.ds: main decoder script file.
  • dscompiler: It's an compiler of decoder script.
    • compile.py: main entry of compiler.
• example： the example code, see detail at here.
• test: the tool and A51-generating script used in test process.
  • generate: contain all A51-generate scripts.
  • compile.py implementation of compiling the .A51 file
  • test_all.py test all A51-generating script in specific module.
  • test_process.py test one of A51-generating script.
  • testconfig.py to configurate which module's which scripts that you want to test in test_all.py.
• tools
  • 51sim: a 8051 insturction simulator.
  • Digital: a visual digital circuit desgin tool.
  • alugen.bat shortcut to generate ALUs' LUT file
  • dscmp.bat shortcut to compile decoder script
  • IAPhost.py a IAP download that allows you to download program to hm51 via UART
  • testall.bat shortcut to test all instruction
  • testprom.bat shortcut to test the support of programmming ROM.

Check The Degin Before Anything

If the hardware design is not correct, it may cause inexplicable problems, so you should first check the design to ensure that the hardware is working correctly.

Environment

• python 3.8.0
• A51.exe/BL51.exe/OH51.exe(keil C51 tools)
• py51

All other tools are provided in "tools" directory.

Run test

copy the following content to terminal:

tools/testtools/testall.bat

Run simulator

open the simulator tools/Digtial.exe, the load the design src/circuit/TOP.dig.

Then load program at this place: