Abstract: A digital oscilloscope processes digitized input waveform data sequences according to a user defined mathematical expression to compute a processed waveform data sequence controlling a periodically updated waveform display on a screen. The waveform data is computed during equivalent time computation passes during each of which pass every Nth data of the waveform data sequence is computed. The first waveform data computed during each pass is selected in a pseudorandom fashion such that each data of the waveform data sequence is computed once every N computation passes. The value of N is suitably chosen so that the duration of each pass is substantially equal to the period between waveform display updates.

Abstract: A data compression circuit has a compression mode of operation where it determines and stores minimum and maximum values of successive sequences of applied data words and provides an output comprising a pair of data words representing the stored minimum and maximum for each sequence, offset by a selected amount. The circuit also has a transparent mode of operation where output data sequences match input data sequences.