A waveform viewer is a software tool for viewing the signal levels of either a digital

Digital circuit

Digital electronics represent signals by discrete bands of analog levels, rather than by a continuous range. All levels within a band represent the same signal state...

 or analog circuit design.

Waveform viewers comes in two varieties:

1. simulation waveform viewers for displaying signal levels of simulated design models, and
2. in-circuit waveform viewers for displaying signal levels captured in-circuit while debugging or testing hardware boards (Also, See Waveform monitor
   Waveform monitor
   A waveform monitor is a special type of oscilloscope used in television production applications. It is typically used to measure and display the level, or voltage, of a video signal with respect to time....
   
   )

Simulation waveform viewers

In integrated circuit design

Integrated circuit design

Integrated circuit design, or IC design, is a subset of electrical engineering and computer engineering, encompassing the particular logic and circuit design techniques required to design integrated circuits, or ICs...

, waveform viewers are typically used in conjunction with a simulation. A waveform view allows an IC designer to see the signal transitions over time and the relation of those signals with other signals in an IC design, which is typically written in a hardware description language

Hardware description language

In electronics, a hardware description language or HDL is any language from a class of computer languages, specification languages, or modeling languages for formal description and design of electronic circuits, and most-commonly, digital logic...

. Simulators can be used to interactively capture wave data for immediate viewing on a waveform viewer; however, for integrated circuit design the usage model is typically to save the output of simulation runs by running batch jobs and to view the waveforms off-line as a static database.

Waveform viewers allow you to zoom in and out over a time sequence, and take measurements between two cursor points. In addition, the waveform view has many ways of displaying signal information, such as in hexadecimal

Hexadecimal

In mathematics and computer science, hexadecimal is a positional numeral system with a radix, or base, of 16. It uses sixteen distinct symbols, most often the symbols 0–9 to represent values zero to nine, and A, B, C, D, E, F to represent values ten to fifteen...

, binary

Binary code

A binary code is a way of representing text or computer processor instructions by the use of the binary number system's two-binary digits 0 and 1. This is accomplished by assigning a bit string to each particular symbol or instruction...

, or a symbolic value.

Most waveform viewers can read an industrial standard waveform database known as Value Change Dump

Value change dump

Value change dump is an ASCII-based format for dumpfiles generated by EDA logic simulation tools. The standard, four-value VCD format was defined along with the Verilog hardware description language by the IEEE Standard 1364-1995 in 1995. An Extended VCD format defined six years later in the IEEE...

 (VCD) or a proprietary wave format. The proprietary wave formats usually have faster record and playback speeds or require smaller memory store space, or save additional signal information for viewing, such as bus transactions.

List of the most well-known viewers

waveform viewer	tool suite	developer	Platform	features	wave formats	Screenshot
VcdView	NA	Ted Rossin	Windows Microsoft Windows Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...	digital	*.vcd
EZwave	Questa ADMS	Mentor Graphics Mentor Graphics Mentor Graphics, Inc is a US-based multinational corporation dealing in electronic design automation for electrical engineering and electronics, as of 2004, ranked third in the EDA industry it helped create...	Linux Linux Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds... , Solaris, Windows Microsoft Windows Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...	analog, RF, digital and mixed-signal	*.wdb, *.tab, *.cou, *.sti, *.tr%, *.ac%, *.sw%, *.vcd, *.fsdb, *.csv, *.swd, *.dofile, *.dof, *.do, *.tcl
Simvision	NCSim NCSim Incisive is a suite of tools from Cadence Design Systems related to the design and verification of ASICs, SoCs, and FPGAs. Incisive is commonly referred to by the name NCSim in reference to the core simulation engine...	Cadence Design Systems Cadence Design Systems Cadence Design Systems, Inc is an electronic design automation software and engineering services company, founded in 1988 by the merger of SDA Systems and ECAD, Inc...	Linux Linux Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds... , Solaris, Windows Microsoft Windows Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...	digital, analog, transactions	*.trn, *.shm, *.vcd
vsim	Modelsim	Mentor Graphics Mentor Graphics Mentor Graphics, Inc is a US-based multinational corporation dealing in electronic design automation for electrical engineering and electronics, as of 2004, ranked third in the EDA industry it helped create...	Linux Linux Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds... , Solaris, Windows Microsoft Windows Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...	digital, analog	*.wlf, *.vcd
finewave/PowerView	FineSim	Magma Design Automation Magma Design Automation Magma Design Automation is a software company in the electronic design automation industry. The company was founded in 1997 and maintains headquarters in San Jose, California, with facilities throughout North America, Europe, Japan, Asia and India....	Linux Linux Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds... , Solaris	digital, analog	*.fsdb, *.vcd
WaveViewer	works with: VeriLogger	SynaptiCAD	Linux Linux Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds... , Solaris, Windows Microsoft Windows Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...	digital, analog, test equipment, free, high capacity, editable	*.btim, *.csdf, *.tdml, *.vcd, 20+ other formats
Wave VCD	works with: CVer	Interconnect Systems Solutions	Windows Microsoft Windows Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...	digital, Free, good-quality	*.vcd
WaveProbe	LogicSim	Zeemz	Windows Microsoft Windows Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...	digital, analog	*.wave
vwave	Undertow	Veritools	Linux Linux Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds... , Solaris, Windows Microsoft Windows Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...	digital, analog, transactions	*.vcd
nWave	Verdi	SpringSoft SpringSoft SpringSoft is a software company that develops cutting edge VLSI design and debugging software. The company was founded with a grant from the Taiwanese National Science Council in February 1996. In 1997, SpringSoft established the company Novas Software in Silicon Valley to market, distribute,...	Linux Linux Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds... , Solaris	digital, analog, transactions, assertions	fsdb, *.vcd
WaveCrave	Analog FastSPICE Platform	Berkeley Design Automation Berkeley Design Automation - Overview :Berkeley Design Automation, Inc. is an electronic design automation software company, headquartered in Santa Clara, California. The company develops software for advanced analog/RF integrated circuit verification. Founded in 2003, the company is funded by Woodside Fund, Bessemer...	Linux Linux Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds... , Solaris	analog, RF, digital	PSF ASCII, PSF binary, tr0, FSDB, Nutmeg ASCII, Nutbin, Nutbinf
Scansion	NA	Logic Poet	Mac OS Mac OS Mac OS is a series of graphical user interface-based operating systems developed by Apple Inc. for their Macintosh line of computer systems. The Macintosh user experience is credited with popularizing the graphical user interface...	digital, analog, TLM transaction viewer, native Mac application	*.vcd, *.scnx
GTKWave GTKWave GTKWave is a fully featured GTK+ based waveform viewer which reads FST, LXT, LXT2, VZT, and GHW files as well as standard Verilog VCD/EVCD files and allows their viewing. GTKWave is developed for Linux, with ports for various other operating systems including Microsoft Windows and Mac OS X...	NA	Tony Bybell	Linux Linux Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds... , Windows Microsoft Windows Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal... , Mac OS Mac OS Mac OS is a series of graphical user interface-based operating systems developed by Apple Inc. for their Macintosh line of computer systems. The Macintosh user experience is credited with popularizing the graphical user interface... , Unix Unix Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...	digital, free/open source	*.lxt (Icarus Verilog), *.lxt2 (Icarus Verilog), *.vzt, *.ghw (GHDL), *.vcd, *.evcd *.fst (Icarus Verilog, CVC, CVER_FST), *.fsdb (if fsdbdebug is present in shell search path)
Styx	Hades	Norman Hendrich	Unix Unix Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...	digital, free/open source	?
Dinotrace	Veripool	Wilson Snyder	Linux Linux Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds... , Solaris, Windows Microsoft Windows Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...	digital, free/open source	*.vcd, *.ascii
Waveform Window	DVE	Synopsys Inc Synopsys Synopsys, Inc. is one of the largest companies in the Electronic Design Automation industry. Synopsys' first and best-known product is Design Compiler, a logic-synthesis tool. Synopsys offers a wide range of other products used in the design of an application-specific integrated circuit...	Linux Linux Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds... , Solaris	digital,analog	VCD,eVCD,VPD
Electric Electric (software) The Electric VLSI Design System is an EDA tool written by Steven M. Rubin.Electric is used to draw schematics and to do integrated circuit layout.It can also handle hardware description languages such as VHDL and Verilog....	Electric Electric (software) The Electric VLSI Design System is an EDA tool written by Steven M. Rubin.Electric is used to draw schematics and to do integrated circuit layout.It can also handle hardware description languages such as VHDL and Verilog....	Static Free Software (staticfreesoft.com)	All (Java)	Integration of schematics and layout with waveform viewer.	tr0, pa0, sw0, ac0, mt0 (Hspice), out (Nanosim), spo (Spice/GNUCap), txt (PSpice), raw (SmartSpice, LTSpice), dump (Verilog).
M1 Waveform Viewer	N/A	ASA Corp (m1ot.com)	Windows Microsoft Windows Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...	No-cost, acquire live data from scopes and digitizers, analog and digital, view multiple waveforms at once, 22 parameter measurements, simple collaboration	tr0, txt, csv, wfm (Tek), isf (Tek), bin (Agilent)
Custom WaveView	Discovery AMS	Synopsys Synopsys Synopsys, Inc. is one of the largest companies in the Electronic Design Automation industry. Synopsys' first and best-known product is Design Compiler, a logic-synthesis tool. Synopsys offers a wide range of other products used in the design of an application-specific integrated circuit...	Linux Linux Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds... , Solaris, HP, Windows Microsoft Windows Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...	Analog, RF, digital and mixed-signal, scripting/batch mode, jitter measurements, DAC toolbox, FFT/iFFT, A->D and D->A conversion, Synopsys/Cadence/Mentor Graphics/JEDAT/Silicon Canvas integration into schematic capture, re-usable measurement templates, HSPICE .measure GUI, digital waveform comparisons, parametric analysis, 3D plots, extremely fast.	Synopsys: HSPICE tr0, sw0, ac0, mt0, hb0, nw0, lis (Binary/ASCII); StarSim wdb, wv, xp (binary); HSIM/NanoSim/XA wdb (binary); HSIM/NanoSim/TimeMill/Powermill out, vector, .mt file (ASCII); Saber AI/PL (binary/ASCII); VCS/Magellan/DVE VPD (binary); WDF format (binary). Cadence: Spectre PSF, WSF (binary/ASCII); runObjFile; PSPICE DAT (binary), Allegro SIM (ASCII); Verilog VCD (ASCII); ModelSim WLF (binary). Mentor Graphics: ELDO/ADMS COU, WDB (binary), AdiT TR0/TB0. SPICE3/SmartSpice raw format (binary/ASCII). Agilent ADS .ds format (binary), TouchStone S-parameters (ASCII). CSDF (Common Simulation Data Format) (ASCII). Novas fsdb files (binary, v4.1). Text file, CSV (comma separated values) format. Other in-house simulator formats: SDIF, MICS, TI-punch (binary). Data from oscilloscopes.

In-circuit waveform viewers

These are built into most logic analyzer

Logic analyzer

A logic analyzer is an electronic instrument which displays signals in a digital circuit. A logic analyzer may convert the captured data into timing diagrams, protocol decodes, state machine traces, assembly language, or correlate assembly with source-level software.Presently, there are three...

, data acquisition

Data acquisition

Data acquisition is the process of sampling signals that measure real world physical conditions and converting the resulting samples into digital numeric values that can be manipulated by a computer. Data acquisition systems typically convert analog waveforms into digital values for processing...

 cards, and automatic test equipment

Automatic test equipment

Automatic or Automated Test Equipment is any apparatus that performs tests on a device, known as the Device Under Test , using automation to quickly perform measurements and evaluate the test results...

. In-circuit waveform viewers are included with products from:

• Tektronix
  Tektronix
  Tektronix, Inc. is an American company best known for its test and measurement equipment such as oscilloscopes, logic analyzers, and video and mobile test protocol equipment. In November 2007, Tektronix became a subsidiary of Danaher Corporation....
  
  
• LabWindows/CVI
  LabWindows/CVI
  LabWindows/CVI is an event-driven, ANSI C programming environment developed by National Instruments. The program was originally released as LabWindows for DOS in 1987, but was soon reinvisioned for the Microsoft Windows platform...
  
  
• Teradyne
  Teradyne
  Teradyne , a US company, is a supplier of automatic test equipment . The company's divisions Semiconductor Test and Systems Test Group, are organized by the products they develop and deliver.-History:...