What is a Logic Analyzer?

A logic analyzer is an electronic instrument that captures and displays multiple signals from a digital system or a digital circuit. It is an excellent tool for verifying and debugging digital designs. A logic analyzer may convert the captured data into timing diagrams, protocol decodes, state machine traces, and assembly language. For debugging elusive, intermittent problems, some logic analyzers can detect glitches, as well as setup-and-hold time violations. During software/hardware integration, logic analyzers trace the execution of the embedded software and analyze the efficiency of the program’s execution. Some logic analyzers correlate the source code with specific hardware activities in your design.

Why use a logic analyzer?

Debugging microprocessor-based designs required more inputs than what conventional analog oscilloscopes could offer. A typical logic analyzer has anywhere from 8 to 136 channels and they are particularly useful for looking at time relationships or data on a bus – for example, a microprocessor address, data, or control bus. They can decode the information on microprocessor buses and display it in a meaningful form.

A logic analyzer is basically used when we need to:

– Debug and verify digital system operation
– Trace and correlate many digital signals simultaneously
– Detect and analyze timing violations and transients on buses
– Trace embedded software execution

Types of Logic Analyzers:

There are three types of logic analyzers: Modular logic analyzers, Portable logic analyzers, and PC-based logic analyzers.

Modular Logic Analyzers:

Modular logic analyzers are the standard form seen in labs that have a chassis and multiple modules. These are some of the more expensive and provide the highest level of functionality to the user. Modules can be added or removed depending on the user in order to increase the functionality. Eg: Modules can be added to increase the number of channels in the Logic Analyzer depending on the user.

Portable Logic Analyzer:

Portable logic analyzers are more portable than modular logic analyzers and provide all the functions that are integrated into a single module with a screen. There may be instances when a smaller analyzer will be required due to restricted budgets or field of service. These test instruments incorporate all elements of the analyzer into a single unit for ease of transportation.

PC based Logic Analyzer:

PC-based logic analyzers are compact in size and they directly interface to a computer via an ethernet or a USB cable. The captured information is displayed to the user via the PC’s display. PC-based logic analyzers are the least expensive but are limited in terms of power compared to modular and portable logic analyzers.