Logic analyzer with trigger specification defined by waveform exemplar

Abstract

Waveform segment(s) of interest in the displayed logic analyzer trace can create the desire in an operator to re-define the trigger specification to be those segments. Those waveform segments are identified to the logic analyzer by drawing a “rubber band” box around them even as they are displayed as part of the trace. The analyzer is instructed to automatically create therefrom, by itself, the desired new trigger specification. It does this by inspecting the captured data corresponding to the contents of the box and creating a description of the associated signal(s) in terms of transitions and steady state conditions. These individual descriptions of activity are then assembled into a trigger specification according to certain rules. More than one box may be drawn. Multiple-boxes may be “stacked” to include waveform segments separated vertically by intervening waveforms for other signals that are to be excluded. Boxed transitions that appear to line up vertically are treated as though they happened at the same time, even if they in actual fact, did not. Multiple boxes may be displaced horizontally, in which case a sequential ordering of separate events is generally implied. Screens having auxiliary menus needed to complete the trigger specification are automatically produced.