CircuitSim

An interafce to perform simulations of gate-level HDL designs from python.

Installation

CircuitSim requires Python3.6 or greater The easiest way to install is via PyPi:

pip install circuitsim

Finally, to install in-place with the source, use:

cd <install location>
git clone https://github.com/circuitgraph/circuitsim.git
cd circuitsim
pip install -e .

In order to perform simulations, you must have at least one of the available simulators installed.

Using the simulator

Simulation can be performed using the CircuitSimulator class.

This allows the simulation to be compiled once and then quieried multiple times without having to recompile.

The CircuitSimulator accepts circuits in the form of circuitgraph Circuit objects.

Vectors are accepted and returned as dictionaries mapping input/output names to logical values (True or False).

Available simulators

Currently, iverilog, verilator, and VCS are supported. In order to use a given simulator, it must be in your PATH.

Usage Example

import random
import shutil

import circuitgraph as cg

from circuitsim import CircuitSimulator


def main():
    # Exercise 3 random inputs patterns 5 times.
    num_trials = 5
    num_vectors = 3
    c = cg.from_lib("c17")
    simulator = CircuitSimulator(c)
    for sim_num in range(num_trials):
        vectors = []
        for _ in range(num_vectors):
            vectors.append({i: random.choice([True, False])
                           for i in c.inputs()})
        sim_results = simulator.simulate(vectors)
        print(f"Simulation {sim_num}")
        print(f"inputs: {vectors}")
        print(f"outputs: {sim_results}")


if __name__ == "__main__":
    main()

Contributing

If you want to develop an improvement for this library, please consider the information below.

Tests are run using the builtin unittest framework. Some basic linting is performed using flake8.

pip instsall flake8
make test

Documentation is built using pdoc3.

pip install pdoc3
make doc

Code should be formatted using black. Pre-commit is used to automatically run black on commit.

pip install black pre-commit
pre-commit install

Pre-commit also runs a few other hooks, including a docstring formatter and linter. Docs follow the numpy documentation convention.