PySHDL 0.1.5

SHDL (Simple Hardware Description Language) is a minimal HDL designed for creating digital circuits and easily simulating them. It compiles directly to C for maximum performance and portability. PySHDL is the Python interface for SHDL.

SHDL - Simple Hardware Description Language

A lightweight hardware description language and Python driver for digital circuit simulation. SHDL provides an intuitive syntax for defining digital circuits and a clean Python API for interacting with them (PySHDL).

Features

• 🚀 Simple Syntax - Easy-to-learn hardware description language
• 🐍 Python Integration - Seamless Python API for circuit simulation
• ⚡ C Backend - Compiles to optimized C code for fast simulation and portability
• 🔧 Command Line Tools - Built-in compiler and utilities
• 📦 Component Reuse - Import and compose reusable circuit components
• 🔢 Constants Support - Use named constants for parameterizable designs

Installation

pip install PySHDL

Quick Start

1. Define a Circuit (SHDL)

Create a file adder.shdl:

use fullAdder::{FullAdder};

component Adder16(A[16], B[16], Cin) -> (Sum[16], Cout) {
    >i[16]{
        fa{i}: FullAdder;
    }
    
    connect {
        A[1] -> fa1.A;
        B[1] -> fa1.B;
        Cin -> fa1.Cin;
        fa1.Sum -> Sum[1];
        
        >i[2, 16]{
            A[{i}] -> fa{i}.A;
            B[{i}] -> fa{i}.B;
            fa{i-1}.Cout -> fa{i}.Cin;
            fa{i}.Sum -> Sum[{i}];
        }
        
        fa16.Cout -> Cout;
    }
}

2. Use in Python

from PySHDL import Circuit

# Load and compile the circuit
circuit = Circuit("adder.shdl")

# Set input values
circuit.poke("A", 42)
circuit.poke("B", 17)
circuit.poke("Cin", 1)

# Run simulation
circuit.step(10)

# Read output
result = circuit.peek("Sum")
print(f"Result: {result}")  # Output: Result: 60

3. Compile from Command Line

# Compile SHDL to C
shdlc adder.shdl -o adder.c

# Compile and build executable
shdlc adder.shdl --optimize 3

CLI Options

shdlc [options] <input.shdl>

Options:
  -o, --output FILE       Output C file (default: <input>.c)
  -I, --include DIR       Add directory to component search path
  -c, --compile-only      Generate C code only, do not compile to binary
  -O, --optimize LEVEL    GCC optimization level 0-3 (default: 3)

Python API

Circuit Class

Circuit(shdl_file, search_paths=None)

Create a new circuit instance from a SHDL file.

Methods:

• poke(port_name, value) - Set an input port value
• peek(port_name) - Read an output port value
• step(cycles) - Advance simulation by N cycles
• reset() - Reset circuit to initial state

Examples

See the examples/ directory for more complete examples:

• interacting.py - Basic circuit interaction
• SHDL_components/ - Reusable component library

Documentation

Github repository: rafa-rrayes/SHDL For more detailed documentation, see DOCS.md

Requirements

• Python >= 3.9
• GCC or compatible C compiler (for circuit compilation)

Author

Rafa Rayes
Email: [e-mail] GitHub: rafa-rrayes

Contributing

Contributions are welcome! Please feel free to submit issues or pull requests.