Spectrum Brands MI.61XX manual Standard generation modes, General description, Programming

General description Standard generation modes

Standard generation modes

General description

The generated data is replayed from the on-board memory. These modes allows generating waveforms at very high sample rates without the need to transfer the data into the board’s on-board memory at high speed. These modes are running totally independent from the PC and don’t need any processing power after being started.

Singleshot mode

The singleshot mode is the most simple output mode for the Spectrum boards. It simply replays the programmed data once after detecting the trigger event. The amount of memory to be replayed can be programmed by software. Any trigger source can be used to start the output. If output should be star- ted immediately one can simply use the software trigger ca- pabilities of the board.

Register	Value	Direction	Description
SPC_SINGLESHOT	41000	r/w	Write a „1“ to enable the singleshot mode (a „0“ disables it)

Continuous Mode

After detetcting the trigger event the programmed data is re- played continuously. On reaching end of the programmed memory size the output starts again with the first sample. The- re’s no gap in output when switching from the last sample to the first sample. The output runs until the users stops it by soft- ware. If not stopped the continuous output runs independent of any other PC components until the system is shut off.

Register	Value	Direction	Description
SPC_SINGLESHOT	41000	r/w	Write a „0“ to disable the singleshot mode
SPC_OUTONTRIGGER	41100	r/w	Write a „1“ to enable the continuous mode

Posttrigger Mode

The posttrigger mode is normally only used when starting the output board together with an acquisiton board.

The data is written to a programmed amount of the on-board memory (memsize). After starting the board the output will im- mediately start and continue to loop. At this point the mode is similar to the continuous mode explained above. After detec- ting a rigger event, a certain programmed amount of data is replayed (posttrigger) and then the replay finishes automati- cally.

Register	Value	Direction	Description
SPC_SINGLESHOT	41000	r/w	Write a „0“ to disable the singleshot mode
SPC_OUTONTRIGGER	41100	r/w	Write a „0“ to disable the continuous mode

Programming

Partitioning the memory

The memory size register defines the length of the data to be replayed. Depending on the mode used this data is replayed once or conti- nuously.

Register	Value	Direction	Description
SPC_MEMSIZE	10000	r/w	Sets the memory size in samples per channel.
SPC_POSTTRIGGER	10100	r/w	Sets the number of samples to be replayed after the trigger event has been detected.

The maximum memsize that can be use for replaying is of course limited by the installed amount of memory and by the number of channels to be replayed. The following table gives you an overview on the maximum memsize in relation to the installed memory.

44 MI.61xx Manual