- A logic analyzer is an electronic instrument that captures and displays multiple signals from a digital system or digital circuit. May convert the captured date into timing diagrams, protocol decodes state machine traces assembly language or may correlate assembly with source level software logic analyzers. They have advanced triggering capabilities and are useful when a user needs to see the timing relationships between many signals in a digital system presently there are three distinct categories of logic analyzers available on the market. Modular lofts which consist of both a cafe or mainframe and logic analyzer modules the mainframe/chassis contains a display controls and control computer and multiple slots into which the actual data capturing hardware is installed.
- The modules each have a specific number of channels and multiple modules may be combined to obtain a very high channel count. While modular logic analyzers are typically more expensive, the ability to combine multiple modules to obtain a high channel count and the generally high performance of modular logic analyzers often justifies the price for the very high end modular logic analyzers. The user often must provide their own host PC or purchase an embedded controller compatible with the system. Portable loss is sometimes referred to as a stand-alone lush portable logic analyzer.
- Integrate everything into a single package with options installed at the factory. While portable logic analyzers generally have lower performance than their modular counterparts. They are often used for general purpose debugging by cost conscious users PC based loss the hardware connects to a computer. Through a USB or ethernet connection and relay the captured signals to the software on the computer. These devices are typically much smaller and less expensive. Because they make use of a PC’s existing keyboard display and CPU a logic analyzer can be triggered on a complicated sequence of digital events. Then capture a large amount of digital data from the system under test suit.
- When logic analyzers first came into use it was common to attach several hundred clips to a digital system. Later specialized connectors came into use the evolution of logic analyzer probes has led to a common footprint that multiple vendors support. Which provides added freedom to end users introduced in april 2002 connector less technology identified by several vendors specific trade names compression probing soft touch d-max has become popular. These probes provide a durable reliable mechanical and electrical connection between the probes. The circuit board was less than 0.5 to 0.7 to call for a loading per signal once. The probes are connected and the user programs the analyzer with the names of each signal and can group several signals together for easier manipulation.
- Next a capture mode is chosen either timing mode. Where the input signals are sampled at regular intervals based on an internal or external clock source or state mode. Where one or more of the signals are defined as clocks and data are taken on the rising or falling edges of these clocks optionally using other signals to qualify. These clocks after the mode is chosen a trigger condition must be set. A trigger condition can range from simple seconds triggering on a rising or falling edge of a single to a very complex. Such as configuring the analyzer to decode the higher levels of the tcp/ip stack and triggering on a certain HTTP packet. At this point the user sets the analyzer to run mode either triggering once repeatedly triggering once the date of our capture can be displayed several ways from the simple showing waveforms or state listings to the complex showing decoded ethernet protocol traffic. Some analyzers can also operate in a compare mode.
- Where they compare each captured date set to a previously recorded data set and hold capture or visually notify the operator. When this date set is either matched or not this is useful for long term empirical testing of recent analyzers. Can even be set to email a copy of the test date to the engineer on a successful trigger. Many digital designs including those events are simulated to detect defects before. The unit is constructed and the simulation usually provides logic analysis displays often complex discrete logic is verified by simulating inputs and testing outputs using boundary scan logic. Analyzer can uncover hardware defects that are not found in simulation. These problems are typically too difficult to model in simulation or too time consuming to simulate and often cross multiple clock domains field programmable gate arrays. Has become a common measurement point for logic analyzers and also used to debug.
- The logic circuit mixed signal oscilloscopes combine the functionality of a digital storage oscilloscope with a logic analyzer. The several benefits of these include the ability to view analog and digital signals together in time and to trigger on either digital or analog signals and capture on the other a few limitations of mixed signal oscilloscopes are that they do not capture state mode data. They have limited channel count and do not provide the analytical depth and inside of a logic analyzer.
ADVERTISEMENT