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Operation Theory
Figure 4-11: Post-Trigger with Retrigger Generation
Iterative Waveform Generation
Users can set IC_counter to generate iterative waveforms, no
matter which Trigger Mode is used. The IC_counter stores the
iteration number. Examples are shown in Figure 4-12 and 4-13.
When IC_counter is disabled, the waveform generation will not
stop until a stop trigger is asserted. For Stop Mode, please
refer to Section 4.2 for details.
An on-board data FIFO is used to buffer the waveform patterns
for wave-form generation. If the size of a single waveform is
smaller than that of the FIFO, after initially loading the data
from the host PC’s memory, the data in FIFO will be re-used
when a single waveform generation is completed. In other
words, it won’t occupy the PCI bandwidth afterwards. How-
ever, if the size of a single waveform were larger than that of
the FIFO, it needs to be intermittently loaded from the host
PC’s memory via DMA, thus PCI bandwidth would be occu-
pied.
If the value specified in UC_counter is smaller than the sample
size of the waveform patterns, the waveform will be generated
piece-wisely. For example, if users defined a 16-sample sine
wave and set the UC_counter to 2, the generated waveform