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List of HDL simulators

From Wikipedia, the free encyclopedia

HDL simulators are software packages that simulate expressions written in one of the hardware description languages, such as VHDL, Verilog, SystemVerilog.

This page is intended to list current and historical HDL simulators, accelerators, emulators, etc.

Proprietary simulators[edit]

List of HDL simulators in alphabetical order by name
Simulator name Author/company Languages Description
Active-HDL / Riviera-PRO Aldec VHDL-1987,-1993,-2002,-2008,-2019 V1995, V2001, V2005, SV2009, SV2012, SV2017 Active-HDL is Aldec's Windows-based simulator with complete HDL graphical entry and verification environment aimed at FPGA and SoC FPGA applications. Riviera-PRO is Aldec's Windows/Linux-based simulator with complete verification environment aimed at FPGA, SoC FPGA and ASIC applications. Both Aldec simulators are the most cost-effective simulators in the industry, with advanced debugging capabilities and high-performance simulation engines, supports advanced verification methodologies such as assertion based verification and UVM. Aldec simulators have the complete VHDL-2008 implementation and the first to offer VHDL-2019 features. Aldec has the most cost-effective commercial simulator in the industry.
Aeolus-DS Huada Empyrean Software Co., Ltd V2001 Aeolus-DS is a part of Aeolus simulator which is designed to simulate mixed signal circuit. Aeolus-DS supports pure Verilog simulation.
HiLo Teradyne Used in 1980s.
Incisive Enterprise Simulator ('big 3') Cadence Design Systems VHDL-1987,-1993,-2002,-2008, V2001, SV2005, SV2009, SV2012, SV2017 Cadence initially acquired Gateway Design, thereby acquiring Verilog-XL. In response to competition from faster simulators, Cadence developed its own compiled-language simulator, NC-Verilog. The modern version of the NCsim family, called Incisive Enterprise Simulator, includes Verilog, VHDL, and SystemVerilog support. It also provides support for the e verification language, and a fast SystemC simulation kernel.
ISE Simulator Xilinx VHDL-93, V2001 Xilinx's simulator comes bundled with the ISE Design Suite. ISE Simulator (ISim) provides support for mixed-mode language simulation including, but not limited to, simulation of designs targeted for Xilinx's FPGAs and CPLDs.
Metrics Cloud Simulator Metrics Technologies SV2012 SystemVerilog simulator used on the Metrics cloud platform. Includes all the standard features of a modern SystemVerilog simulator including debug, APIs, language and testbench support.
ModelSim / Questa ('big 3') Mentor Graphics VHDL-1987,-1993,-2002,-2008, V2001, SV2005, SV2009, SV2012, SV2017 The original Modeltech (VHDL) simulator was the first mixed-language simulator capable of simulating VHDL and Verilog design entities together. In 2003, ModelSim 5.8 was the first simulator to begin supporting features of the Accellera SystemVerilog 3.0 standard.[1] In 2005 Mentor introduced Questa to provide high performance Verilog and SystemVerilog simulation and expand Verification capabilities to more advanced methodologies such as Assertion Based Verification and Functional Coverage. Today Questa is the leading high performance SystemVerilog and Mixed simulator supporting a full suite of methodologies including industry standard OVM and UVM. ModelSim is still the leading simulator for FPGA design.
MPSim Axiom Design Automation V2001, V2005, SV2005, SV2009 MPsim is a fast compiled simulator with full support for Verilog, SystemVerilog and SystemC. It includes Designer, integrated Verilog and SystemVerilog debugging environment and has built-in support for multi-cpu simulation.
PureSpeed Frontline V1995 The first Verilog simulator available on the Windows OS. The simulator had a cycle-based counterpart called 'CycleDrive'. FrontLine was sold to Avant! in 1998, which was later acquired by Synopsys in 2002. Synopsys discontinued Purespeed in favor of its well-established VCS simulator.
Quartus II Simulator (Qsim) Altera VHDL-1993, V2001, SV2005 Altera's simulator bundled with the Quartus II design software in release 11.1 and later. Supports Verilog, VHDL and AHDL.
SILOS Silvaco V2001 As one of the low-cost interpreted Verilog simulators, Silos III, from SimuCad, enjoyed great popularity in the 1990s. With Silvaco's acquisition of SimuCad, Silos is part of the Silvaco EDA tool suite.
SIMILI VHDL Symphony EDA VHDL-1993 Another low-cost VHDL simulator with graphical user interface and integrated waveform viewer. Their web site was not updated for quite some time now. You can no longer purchase the software. The free version does work but you have to request a license via email.
SMASH Dolphin Integration V1995, V2001, VHDL-1993 SMASH is a mixed-signal, multi-language simulator for IC or PCB designs. It uses SPICE syntax for analog descriptions, Verilog-HDL and VHDL for digital, Verilog-A/AMS, VHDL-AMS and ABCD (a combination of SPICE and C) for analog behavioral, and C for DSP algorithms.
Speedsim Cadence Design Systems V1995 Cycle based simulator originally developed at DEC. The DEC developers spun off to form Quickturn Design Systems. Quickturn was later acquired by Cadence, who discontinued the product in 2005. Speedsim featured an innovative slotted bit-slice architecture that supported simulation of up to 32 tests in parallel.
Super-FinSim Fintronic V2001 This simulator is available on multi-platform, claiming IEEE 1364-2001 compliance.
TEGAS / Texsim TEGAS/CALMA/GE TDL (Tegas Design Language) First described in 1972 paper, used in 1980s by ASIC vendors such as LSI Logic, GE.
VCS ('big 3') Synopsys VHDL-1987,-1993,-2002,-2008, V2001, SV2005, SV2009, SV2012, SV2017 Originally developed by John Sanguinetti, Peter Eichenberger and Michael McNamara under the startup company Chronologic Simulation, which was acquired by ViewLogic Systems in 1994. ViewLogic was subsequently acquired by Synopsys in 1997. VCS has been in continuous active development, and pioneered compiled-code simulation, native testbench and SystemVerilog support, and unified compiler technologies. Today, VCS provides comprehensive support for all functional verification methodologies and languages (including VHDL, Verilog, SystemVerilog, Verilog AMS, SystemC, and C/C++), and advanced simulation technologies including native low power, x-propagation, unreachability analysis, and fine-grained parallelism.
Verilogger Extreme / Pro SynaptiCAD V2001, V1995 Verilogger Pro is a low-cost interpreted simulator based on Elliot Mednick's VeriWell code base. Verilogger Extreme is a newer, compiled-code simulator that is Verilog-2001 compliant and much faster than Pro.
Verilog-XL Cadence Design Systems V1995 The original Verilog simulator, Gateway Design's Verilog-XL was the first (and only, for a time) Verilog simulator to be qualified for ASIC (validation) sign-off. After its acquisition by Cadence Design Systems, Verilog-XL changed very little over the years, retaining an interpreted language engine, and freezing language-support at Verilog-1995. Cadence recommends Incisive Enterprise Simulator for new design projects, as XL no longer receives active development. Nevertheless, XL continues to find use in companies with large codebases of legacy Verilog. Many early Verilog codebases will only simulate properly in Verilog-XL, due to variation in language implementation of other simulators.
Veritak Sugawara Systems V2001 It is low-cost and Windows-based only. It boasts a built-in waveform viewer and fast execution.
Xilinx Simulator (XSIM) Xilinx VHDL-1993,-2002 (subset),-2008 (subset),[2] V2001, V2005, SV2009, SV2012, SV2017 Xilinx Simulator (XSIM) comes as part of the Vivado design suite. It is a compiled-language simulator that supports mixed language simulation with Verilog, SystemVerilog, VHDL and SystemC language. It supports standard debugging tool such as step through code, breakpoints, cross-probing, value probes, call stack and local variable Window. The waveform viewer in Xilinx Simulator supports virtual bus, signal grouping, analog view & protocol viewing features. It also supports UVM 1.2 and functional coverage for advanced verification. It supports both GUI and batch mode via TCL script and allows simulation of encrypted IPs. Xilinx Simulator supports SystemVerilog Direct Programming Interface (DPI) and Xilinx simulator interface (XSI) to connect C/C++ model with Xilinx simulator.
Z01X WinterLogic (acquired by Synopsys 2016) V2001, SV2005 Developed as a fault simulator but can also be used as a logic simulator.

Some commercial proprietary simulators (such as ModelSim) are available in student, or evaluation/demo editions. These editions generally have many features disabled, arbitrary limits on simulation design size, but are sometimes offered free of charge.

Free and open-source simulators[edit]

Verilog simulators[edit]

List of Verilog simulators in alphabetical order
Simulator name License Author/company Supported languages Description
Cascade BSD VMware Research V2005 (large subset) Just-in-Time Verilog simulator and compiler for FPGAs allowing to instantly run both synthesizable and unsynthesizable Verilog on hardware
CVC Perl style artistic license [3] Tachyon Design Automation V2001, V2005 CVC is a Verilog HDL compiled simulator. CVC has the ability to simulate in either interpreted or compiled mode.
GPL Cver GPL Pragmatic C Software V1995, minimal V2001 This is a GPL open-source simulator. It is a pure simulator. This simulator is not fully IEEE 1364-2001 compliant. It does not support generate and constant functions.
Icarus Verilog GPL2+ Stephen Williams V1995, V2001, V2005, limited SV2005/SV2009/SV2012 Also known as iverilog. Good support for Verilog 2005, including generate statements and constant functions.
Isotel Mixed Signal & Domain Simulation GPL ngspice, Yosys communities and Isotel V2005 Open-source mixed signal ngspice simulator in combination with verilog synthesis software called Yosys and Isotel extension for embedded C/C++ (or other) co-simulation.
LIFTING A. Bosio, G. Di Natale (LIRMM) V1995 LIFTING (LIRMM Fault Simulator) is an open-source simulator able to perform both logic and fault simulation for single/multiple stuck-at faults and single event upset (SEU) on digital circuits described in Verilog.
OSS CVC Perl style artistic license Tachyon Design Automation V2001, V2005 CVC is a Verilog HDL compiled simulator. CVC has the ability to simulate in either interpreted or compiled mode. Source code is available under a Perl style artistic license.
TkGate GPL2+ Jeffery P. Hansen V1995 Event driven digital circuit editor and simulator with tcl/tk GUI based on Verilog. Includes Verilog simulator Verga.
Verilator GPL3 Veripool V1995, V2001, V2005, SV2005, SV2009, SV2012, SV2017, SV2023 Verilator is a very high speed open-source simulator that compiles Verilog to multithreaded C++/SystemC. Verilator previously required that testbench code be written as synthesizable RTL, or as a C++ or SystemC testbench, because Verilator did not support behavioral Verilog. These are now supported.
Verilog Behavioral Simulator (VBS) GPL Lay H. Tho and Jimen Ching V1995 Supports functions, tasks and module instantiation. It has a few features, but this release has enough for a VLSI student to use and learn Verilog. Supports only behavioral constructs of Verilog and minimal simulation constructs such as 'initial' statements.
VeriWell GPL2 Elliot Mednick V1995 This simulator used to be proprietary, but has recently become GPL open-source. Compliance with 1364 is not well documented. It is not fully compliant with IEEE 1364–1995.

VHDL simulators[edit]

List of VHDL simulators in alphabetical order
Simulator name License Author/company Supported languages Description
FreeHDL GPL2+ Edwin Naroska VHDL-1987, VHDL-1993 A project to develop a free, open source, VHDL simulator
GHDL GPL2+ Tristan Gingold VHDL-1987, VHDL-1993, VHDL-2002, partial VHDL-2008, partial VHDL-2019[4] GHDL is a complete VHDL simulator, using the GCC technology.
NVC GPL-3.0-or-later Nick Gasson and contributors VHDL-1993, VHDL-2002, VHDL-2008, partial VHDL-2019[5] NVC is a GPLv3 VHDL compiler and simulator. It is available for various distributions of Linux, macOS, Windows (via Cygwin or MSYS2), and OpenBSD.


Tag Description
V1995 IEEE 1364-1995 Verilog
V2001 IEEE 1364-2001 Verilog
V2005 IEEE 1364-2005 Verilog
SV2005 IEEE 1800-2005 SystemVerilog
SV2009 IEEE 1800-2009 SystemVerilog
SV2012 IEEE 1800-2012 SystemVerilog
SV2017 IEEE 1800-2017 SystemVerilog
SV2023 IEEE 1800-2023 SystemVerilog
VHDL-1987 IEEE 1076-1987 VHDL
VHDL-1993 IEEE 1076-1993 VHDL
VHDL-2002 IEEE 1076-2002 VHDL
VHDL-2008 IEEE 1076-2008 VHDL
VHDL-2019 IEEE 1076-2019 VHDL

See also[edit]


  1. ^ http://www.sutherland-hdl.com/papers/2004-Mentor-U2U-presentation_SystemVerilog_and_ModelSim.pdf [bare URL PDF]
  2. ^ https://support.xilinx.com/s/article/76459
  3. ^ "Open Source License and FAQ | Tachyon Design-Automation". www.tachyon-da.com. Retrieved 2022-11-03.
  4. ^ Main features, ghdl, 2023-10-01, retrieved 2023-10-02
  5. ^ "NVC README file". GitHub. Retrieved 11 August 2023.