Logic analyzers perform trace measurements . The HP 1630A/D/G models are interactive state and timing analyzers for use in the design and troubleshooting of microprocessor based systems . An analyzer traces activity from several points during a period of system operating time. Theanalyzer may perform both state and timing measurements together and interactively control the capture of information in each of these two functions. General Information Model 1630A/D/G The analyzer can perform overview measurements with which the performance of code modules in softwareintensive systems may then be analyzed . Overview measurements available in all three 1630 models include state and time interval histograms. The 1630G has added overview measurement features that enhance the state label histogram andallow time position and linkage measurements . Thelogic analyzers can be described as having two basic functions, that of state and timing, and have special features in each function which are listed below.