Electric VLSI — The Complete Guide: Open-Source Chip Layout and Schematic Design

Electric is an open-source system for designing integrated circuits: layout of transistors and layers, schematics, and cross-checking between them. It is written in Java, developed by Static Free Software, and has been used for many years in university VLSI courses.

Electric VLSI

Static Free Software

An IC and schematic design system covering layout, schematics and simulation links.

Electrical & ElectronicsCompletely FreeOpen SourceLinuxmacOSWindowsElectronics Design (EDA)

Get it from the vendor

What you get

• Layout editor — drawing layers, contacts and transistors according to a technology file.
• Schematic editor — transistor- or gate-level schematics linked to the layout.
• DRC and LVS — design rule checks and layout-versus-schematic comparison.
• Technology files — several built-in processes, with the option to define more.
• Export for simulation — SPICE netlists and standard formats such as GDS.

What to know

Electric uses a connectivity-based approach: the layout keeps the connections between components even as you move them. That differs from commercial tools and takes time to get used to. Development has been fairly slow in recent years, but the program is stable and well documented. It suits learning and research, not as a replacement for industrial tools on advanced processes.

Related tools

To simulate the netlist — ngspice. To synthesise logic from Verilog — Yosys. To simulate digital blocks — Icarus Verilog.

Ngspice

Ngspice Project

Open-source SPICE simulator — DC, AC, transient and noise. The engine behind KiCad simulation.

Electrical & ElectronicsCompletely FreeOpen SourceLinuxmacOSWindowsSimulation & FEAElectronics Design (EDA)

Get it from the vendor

Yosys — RTL Synthesis for FPGA

YosysHQ / Claire Wolf

Open-source synthesis tool that turns Verilog into a gate-level netlist, the basis of a fully open FPGA flow.

Electrical & ElectronicsCompletely FreeOpen SourceLinuxmacOSWindowsElectronics Design (EDA)

Get it from the vendor

Icarus Verilog

Stephen Williams

A Verilog compiler and simulator for digital design work.

Electrical & ElectronicsCompletely FreeOpen SourceLinuxmacOSWindowsSimulation & FEAElectronics Design (EDA)

Get it from the vendor

Xyce — Parallel Analog Circuit Simulator

Sandia National Laboratories

Sandia National Laboratories’ SPICE simulator, built for very large circuits and parallel execution.

Electrical & ElectronicsCompletely FreeOpen SourceLinuxmacOSWindowsSimulation & FEAElectronics Design (EDA)

Get it from the vendor

The bottom line

Electric is a free way to learn chip design end to end — from schematic to checked layout — without an expensive licence.

Further reading

• ngspice — The Complete Guide: The Open-Source SPICE Simulator, Including Inside KiCad
• Yosys — The Complete Guide: Verilog Synthesis and a Fully Open FPGA Flow
• Free Electronics and PCB Software — Alternatives to Altium, OrCAD and the Simulators