Logic analyzers

For generating and analyzing logic event states, we can employ logic analyzers, logic generators and logic test systems. The logic generator provides excitation to the circuits which is to be analyzed. The logic analyzer analyzes the timing of the digital/logical function and sequence of complex digital events including detection and display. The main four parts of a logic analyzer are data acquisition, data storage, control and triggering and display format. Data acquisition involves reception of data from the test system with variable threshold level for various types of logics such as TTL, ECL and CMOS. An analyzer clock determines the asynchronous mode acquisition sampling rate. The data storage unit stores all the parallel input data. The method of ‘word recognition’ is used for control and triggering in logic analyzers. For external triggering, a separate trigger input is provided. Display formats used here are timing diagram, histogram and state table. Logic probe which is a small hand held instrument can also be used for measuring and analyzing logic events and states.