Xschem Schematic Editor

Overview

Xschem is a free and open-source EDA CAD application for schematic capture, circuit design, netlisting, and simulation. It supports analog, digital, and mixed-signal circuit design and is especially popular for analog VLSI (chip) design where it has been in use for over 20 years, receiving very frequent updates.

Xschem allows creation of hierarchical representations of circuits with a top-down approach. By focusing on interfaces, hierarchy, and instance properties a complex system can be described in terms of simpler building blocks. A netlist can be generated from the drawn schematic as SPICE, Verilog, or VHDL, allowing simulation of the circuit.

Xschem is developed by Stefan Schippers with source hosted on GitHub.

Screenshot of Xschem showing a circuit simulation

Features

Integrates seamlessly with the sky130 Open PDK, with a wide range of examples that can be simulated
Hierarchical schematic drawings with no limits on size
Any schematic object can have any properties (generics in VHDL, parameters in Spice or Verilog)
New Spice/Verilog primitives can be created; netlist format can be defined by the user
Ability to export SPICE netlists that can be imported directly into the Magic VLSI layout tool, enabling creation of parametric ASIC layouts
Tcl extension language allows the creation of scripts; any user command in the drawing window has an associated Tcl comand
Verilog / VHDL / Spice netlist, ready for simulation
Behavioral Verilog / VHDL code can be embedded as one of the properties of the schematic block
Lightweight software design
High-performance native rendering code gives good speed even on very big circuits
Open text-based file format

Documentation

Download & Install

Linux/Unix

Xschem is primarily intended for Linux/Unix systems. Comprehensive download and installation instructions are found here, but below is an easy way to obtain Xschem, build it from source, and install it on Ubuntu Linux or Debian:

# Install prerequisite packages:
sudo apt install \
    autoconf libtool automake libxaw7-dev libreadline-dev \
    tcsh csh tcl-dev tk-dev libcairo2-dev flex bison \
    libxpm-dev libxaw7-dev python3-pip libomp-dev

# Clone, build, and install Xschem:
git clone https://github.com/StefanSchippers/xschem.git xschem-src
cd xschem-src
./configure
make sudo make install
xschem --version
# => 3.4.5

# OPTIONALLY remove Xschem source from your system afterwards:
# cd .. && rm -rf xschem-src

Windows

Xschem can also be used on Windows systems: