8-bit CPU implemented using logic ICs
I am currently working on designing an 8-bit processor and implementing it using logic ICs (Integrated Circuits) on a PCB (printed circuit board). The project part of Rowan University's Robotics and Automation Society (RAS), and I am leading the endeavor.
This project still in its initial design phase at the time of writing this, so not much is set in stone.
The architecture is mostly designed, and will implement 17 instructions, including conditional branching with 14 conditions. It implements a Hardvard-style architecture with a separate interface for data and program memory.
The architecture is being tested using a Verilog HDL model, and simulated using Quartus and Modelsim software. The verilog code can be found in the Github repository
Logic ICs are to be used, which are Integrated Circuits, or 'chips,' which implement basic logic functions (logic gates, multiplexors, memory, timers, etc.) Most of the logic ICs are from the classic 74xx series. One of the key reasons to use this series, even though it is quite old, is due to the high current output. This means LEDs can be driven directly directly from the logic.
The plan is to create several PCBs, for different parts of the processor (such as register file, ALU, control unit, etc.) which all connect to a main PCB. This initial setup will allow individual testing of each module, for much easier debugging.
An RTL (register-transfer level) diagram of the processor's datapath is shown below.