Operating Manual Vol 1 - ES Documentation

SMIQDigital Modulation2.10.5.2 External Parallel Modulation DataParallel data can be fed as symbols via the PAR DATA interface (DATA-D7, -D6 to D0). Either anexternal symbol clock (SYMBCLK) or the internal symbol clock can be used. The data at the active edgeof the symbol clock have to be in a stable state. The following figures show the timings at the interface.In the two examples shown below, the active clock edge is assumed to be positive.DATA-D7 (input)SYMBCLK (input)Fig. 2-57External parallel data and symbol clockData change should take place only on the negative clock edge.SYMBCLK (output)DATA-D7 (input)Internal dataclockFig. 2-58External parallel data and symbol clockSYMBOL CLOCK = High marks the LSB. A status change of DATA and SYMBOL CLOCKshould be performed synchronously.External serial modulation data is selected in the menu by SOURCE-SOURCE-EXT_SER.For modulation types with less than 8 bit/symbol, line DATA-D7 is always the MSB. For QPSKmodulation, for example (2 bit/symbol), data lines DATA-D7 and DATA-D6 are used.Note:BITCLK pin on the PARDATA interface is an output. Synchronization to an external bitclock is not possible in this mode.External parallel modulation data is selected in the menu by SOURCE-SOURCE-EXT_PAR.1125.5555.03 2.97E-9