Abstract: A timing measurement system for displaying data path and clock jitter moves an internal copy of the data clock with respect to the incoming data and clock to acquire sets of samples for each data path and the clock at sequential delay intervals. A reference time is established by examining the clock sets and determining skew extremes defined by the times when the values within a set are no longer all at one state and when the values are all at the other state. The skew extremes are averaged to establish the reference time. Likewise each data path set is examined to determine skew extremes, and the skew extremes are displayed as shaded areas with respect to the reference time for each data path. Also the clock signal is converted to a stable clock signal that is also compared in a like manner to the input clock to establish skew extremes that are displayed about the reference time as clock jitter.

Abstract: A system for providing concurrent access to an addressable memory space by a plurality of data processing devices includes a plurality of independently accessible memory banks, each memory bank providing a separate portion of the addressable memory space. A memory management unit includes address and data multiplexers corresponding to each memory bank for providing access by any selected one of the data processing devices to the corresponding memory bank and also includes circuits for controlling the multiplexers to permit different processing devices to access different memory banks at the same time while arbitrating competing demands for the same memory bank.

Abstract: A digital oscilloscope includes an amplifier having adjustable gain and offset for producing an output signal in response to an input signal, a triggering system for producing a trigger status signal when the amplifier output signal reaches an adjustable trigger level, and a digitizer for generating a waveform data sequence representing magnitudes of samples of the amplifier output signal acquired at various times with respect to assertion of the trigger status signal. The oscilloscope produces a waveform display on a screen according to the waveform data sequence produced by the digitizer and automatically adjusts the amplifier gain and offset, the trigger level, and the sampling rate of the digitizer so that the waveform data produced by the digitizer provides for a waveform display suitably representative of the time dependent behavior of the input signal.