rp2040-pio-emulator 0.19.0

RP2040 emulator for the testing and debugging of PIO programs

Introduction

This repository contains an emulator for the Programmable Input/Output (PIO) blocks that are present within the Raspberry Pi Foundation’s RP2040 Microcontroller. It is designed to assist in the analysis of PIO programs and to help you by:

• Enabling unit tests to be written.

• Answering questions such as: How many clock cycles are being consumed?

• Supporting the visualization of GPIO outputs over time.

• Providing alternatives to debugging on real hardware, which can be time consuming.

Examples

Pimoroni Blinkt! with Unit Test

An annotated example which demonstrates one approach to writing unit tests for PIO programs by using an emulator. The PIO program itself is very primitive and sets all eight LEDs of a Pimoroni Blink! to a single hard-coded colour. Perhaps you would to like to try re-factoring it? Don’t forget to check that the unit-test still passes!

Jupyter Notebook

The emulator can also be used from within Jupyter Notebooks. The screenshot below is taken from the examples/jupyter-notebook/square_wave_example.ipynb notebook that is included within this repository.

Limitations

This software is under development and currently has limitations - the notable ones are:

1. Only supports a sub-set of the available instructions:

   • JMP (PIN and !OSRE variants not implemented)

   • MOV (some variants and operations not implemented)

   • OUT (PC, ISR and EXEC destinations not implemented)

   • PULL (IfEmpty not implemented)

   • SET

   • WAIT (IRQ variant not implemented)

2. No support for OUT, SET or IN pin-sets; all pin numbers are with respect to Pin 0.

3. Pin-sets do not wrap after GPIO 31.

4. No direct support for the concurrent running of multiple PIO programs; a single State Machine is emulated and not an entire PIO block.