A waveform viewer is a
software tool
A programming tool or software development tool is a computer program that software developers use to create, debug, maintain, or otherwise support other programs and applications. The term usually refers to relatively simple programs, that can ...
for viewing the signal levels of either a
digital
Digital usually refers to something using discrete digits, often binary digits.
Technology and computing Hardware
*Digital electronics, electronic circuits which operate using digital signals
** Digital camera, which captures and stores digital ...
or
analog circuit
Analogue electronics ( en-US, analog electronics) are electronic systems with a continuously variable signal, in contrast to digital electronics where signals usually take only two levels. The term "analogue" describes the proportional relat ...
design.
[Janick Bergeron, ''Writing Testbenches: Functional verification of HDL Models'', Kluwer Academic Publishers, 2000]
Waveform viewers comes in two varieties:
# simulation waveform viewers for displaying signal levels of simulated design models, and
# in-circuit waveform viewers for displaying signal levels captured in-circuit while debugging or testing hardware boards (see also
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.
The level of a video signal usually cor ...
)
Simulation waveform viewers
In
integrated circuit design
Integrated circuit design, or IC design, is a sub-field of electronics engineering, encompassing the particular logic and circuit design techniques required to design integrated circuits, or ICs. ICs consist of miniaturized electronic compon ...
, waveform viewers are typically used in conjunction with a
simulation
A simulation is the imitation of the operation of a real-world process or system over time. Simulations require the use of Conceptual model, models; the model represents the key characteristics or behaviors of the selected system or proc ...
. 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
In computer engineering, a hardware description language (HDL) is a specialized computer language used to describe the structure and behavior of electronic circuits, and most commonly, digital logic circuits.
A hardware description language en ...
. 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
In mathematics and computing, the hexadecimal (also base-16 or simply hex) numeral system is a positional numeral system that represents numbers using a radix (base) of 16. Unlike the decimal system representing numbers using 10 symbols, he ...
, binary, or a symbolic value
Symbolic may refer to:
* Symbol, something that represents an idea, a process, or a physical entity
Mathematics, logic, and computing
* Symbolic computation, a scientific area concerned with computing with mathematical formulas
* Symbolic dynamic ...
.[
Most waveform viewers can read an industrial standard waveform database known as ]Value Change Dump
Value Change Dump (VCD) (also known less commonly as "Variable 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 descripti ...
(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
A bus (contracted from omnibus, with variants multibus, motorbus, autobus, etc.) is a road vehicle that carries significantly more passengers than an average car or van. It is most commonly used in public transport, but is also in use for char ...
.[
]
In-circuit waveform viewers
These are built into most logic analyzer
A logic analyzer is an electronic instrument that captures and displays multiple signals from a digital system or digital circuit. A logic analyzer may convert the captured data into timing diagrams, protocol decodes, state machine traces, ass ...
, 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, abbreviated by the acro ...
cards, and automatic test equipment
Automatic test equipment or automated test equipment (ATE) is any apparatus that performs tests on a device, known as the device under test (DUT), equipment under test (EUT) or unit under test (UUT), using automation to quickly perform measurements ...
. In-circuit waveform viewers are included with products from:
* Tektronix
Tektronix, Inc., historically widely known as Tek, is an American company best known for manufacturing test and measurement devices such as oscilloscopes, logic analyzers, and video and mobile test protocol equipment.
Originally an independent ...
* LabWindows/CVI
LabWindows/CVI (CVI is short for C for Virtual Instrumentation) is an ANSI C programming environment for test and measurement developed by National Instruments. The program was originally released as LabWindows for DOS in 1987, but was soon rev ...
* Teradyne
Teradyne, Inc. is an American automatic test equipment (ATE) designer and manufacturer based in North Reading, Massachusetts. Teradyne's high-profile customers include Samsung, Qualcomm, Intel, Analog Devices, Texas Instruments and IBM.
Histo ...
See also
* List of HDL simulators
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, emul ...
, such as such as VHDL, Verilog, SystemVerilog
References
{{Reflist
Logic design