Chip designs are the foundation of the electronics industry. Microprocessors, microcontrollers, integrated circuits (ICs), application-specific ICs, and memory functions operate from this foundation.
Today's ICs are a complex interconnection of millions and billions of transistors. Along with a basic knowledge of electronic devices and circuits, those interested in or seeking a career in circuit design should also be familiar with an Electronic Design Automation (EDA) tool for VLSI.
Analog and digital circuits are the two main types of electronic circuits with different design flows. They both start with similar concepts but quickly change as they go. Analog Mixed Signal is another option that merges analog and digital, offering an advanced design concept for VLSI engineers of any stream.
The chip design uses a programming language, Hardware Description Language (HDL). Verilog, VHDL and SystemVerilog are the most popular HDL languages. Those familiar with computer programming languages – such as C/C++, Matlab/Simulink, Embedded C, or Python – will likely learn HDL with ease.
However, those who are new to programming can learn HDL from scratch by selecting any of the available options. Additionally, C++ or Python are required to understand the scripts. EDA tools are necessary for designing, testing, and verifying circuits. There is open source and licensed software for VLSI design. Students or beginners can start with open source tools.
In this article, we will explore some of the top EDA tools for VLSI design. Some of these tools are open source and can be downloaded for free. Others are industry standards for VLSI engineering.
Alliance/ Coriolis (open source) – a complete toolkit for VLSI design, offering all CAD tools and libraries in the suite for free use under the GNU General Public License (GPL). This is except Hurricane, which is under the LGPL and Si2 LEF/DEF parser drivers which are under the Apache License, version 2.0.
The toolset includes a VHDL compiler, simulator, logic synthesis tool, automatic find and route tools, and a portable CMOS library. Binary packages for installing Alliance are available for Ubuntu LTS, Mac OS X, Fedora, RedHat Enterprise Linux 6 (RHEL6), and RHEL clones like CentOS6 and Scientific Linux 6. For other operating systems, the package can be rebuilt from source .
The latest toolset includes updated alternatives such as Yosys for logic synthesis and GHDL for simulation. Alliance tools are digital-only, analog-only, or mixed. As an open source tool and a complete toolset for VLSI design, it is excellent for beginners. Alliance binaries, source code, cell libraries, and documentation are freely available.
Synopsis – Leading provider of EDA services, Synopsis provides VLSI tools for logic synthesis, simulators (VHDL, Verilog and SystemVerilog), automatic find and route tools, behavioral synthesis, static timing analysis, transistor-level circuit simulation and verification format. These tools run on UNIX-like operating systems and require a license. They can be purchased from synopsys.com and activated online for one or multiple workstations.
Synopsys also offers tools for silicon design, verification, engineering, and lifecycle management.
Cadence – a provider of semiconductor EDA and IP tools with diverse options for design, synthesis, simulation, layout, DRC verification, LVS verification, and parasitic capacitance verification. Some of the main tools used for VLSI design, simulation and layout include ICMS, Composer, Analog Artist, cdsSPICE, Spectre, Virtuoso and DFII. These are all licensed tools available for purchase from Cadence.
Xilinx – Xilinx's EDA tools use their own chips. Xilinx Vivado Design Suite is the current EDA toolset for high-level synthesis, simulation, and layout. The Vivado Design Suite includes Vivado High-Level Synthesis, Vivado Simulator, Vivado IP Integrator and Vivado TCL Store. These licensed tools support the design of Xilinx 7-series FPGA products. Xilinx ISE was discontinued in 2013 and is no longer supported.
SiemensEDA – formerly Mentor Graphics, Siemens EDA provides a range of tools for IC design, simulation and verification. Key tools for VLSI engineering include Catapult for high-level synthesis, Precision for FPGA synthesis, Oasys-RTL for logic synthesis, Caliber Design Solutions for DFM verification and optimization, Aprisa for digital IC implementation, Custom IC for custom IC design ( such as photonics and MEMS), PowerPro for low power optimization, Tessent Silicon Lifecycle Solutions for silicon lifecycle testing and management, and mPower for power integrity analysis. All these tools are licensed.
Silvaco – a leading supplier of EDA, CAD technology and semiconductor IP. Silvaco's TCAD software solutions are a complete suite of tools, which include Victory Atomistic for nanostructure simulation, Victory Device for device simulation, Victory Process for process simulation, Victory Mesh for meshing and solid modeling, Hipex for RC parasitic extraction full-chip rules-based, Victory RCx Pro for RC Extractor for realistic 3D structures, VWF (Virtual Wafer Fab), and interactive tools for pre- and post-processing.
Silvaco also offers a complete analysis, layout and design environment for analog, mixed-signal, schematic-driven RF circuits.
Electrical (open source) – a Java-based EDA tool for VLSI design and layout using VHDL and Verilog. It is available as a GNU project and can be used for synthesis and analysis, including logic synthesis, routing, layout and schematics, simulation, and design rule verification. Unfortunately, the software is no longer actively supported, but bug fixes are available. Electric is worth a try for those interested in a different design approach than typical VLSI tools.
Glade – A free alternative to Cadence, Glade is an IC schematic and layout editor. It offers integrated DRC, extraction, and LVS, enabling the design and verification of schematics and layouts in a single IDE. Glade can be extended using Python scripts and SWIG encapsulation of C++ functions. Along with Linux, Mac OS X and other UNIX-like systems, it can also be downloaded for Windows. The user interface and operation of the software are similar to Cadence.
