CompuScope SDK Manua.. - Egmont Instruments

memory counter overflow rolls over to zero. In the second diagram, Pre-Trigger data lies between ZEROand Trigger Address and Post Trigger between Trigger Address and End Address.Timing Diagrams for CompuScope CaptureAt the start of capture on the CompuScope board, the GET DATA signal is strobed low. This clears theTRIGGER and RAM FULL signals and their status bits and initializes the data acquisition counters toZERO. The BUSY signal and its status bit are now set to high. At this point, the data conversion processbegins and data are stored in the on-board memory at each sample clock. The memory is configured as acircular buffer.At some point a trigger event occurs. This starts another counter (one section of an 8254 counter chip).This is the sample depth counter. When it expires, the BUSY signal and status bit are cleared, which endsthe data acquisition process. A complete timing diagram illustrating a data acquisition in which memorydoes not get filled is shown below.Page 16CompuScope SDK Manual