JYTEK PCIe-69814 Series, User Manual

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To achieve sampling rates other than 80MS/s, a number for scan interval counter needs only
be specified. For example, if the scan interval counter is set as 2, the equivalent sampling
rate is 80MS/s / 2 = 40MS/s. If as 3, the equivalent sampling rate is 80MS/s / 3 = 26.66MS/s,
and vice versa. The scan interval counter is 16 bits in width, therefore the lowest sampling
rate is 1.221kS/s (80MS/s / 65535).
TIMEBASE
DATA
D1
Acquisition
In Progress
Trigger
Acquisition is initiated following this clock edge
D1
ScanIntrv = 1
D2 D3 D4 D5 D6 D7 D8 D9 D10
D2 D3 D4 D5 D6
D1
4 D 3 D 2 D
ScanIntrv = 2
ScanIntrv = 3
Figure 3-14: Varying Sampling Rates by Adjusting Scan Interval Counter
Counter Name Length Valid Value Description
ScanIntrv 16-bit 1-65535 Timebase divider to achieve equivalent
sampling rate of the digitizer, where
Sampling rate = Timebase / ScanIntrv
DataCnt 31-bit 1-2147483647 Specifies the amount of data to be
acquired: 1 - 2147483648 for pre-trig
or mid-trig mode peration
trigDelayTicks 16-bit 1 -65535 Indicates time between a trigger event
and commencement of acquisition.
The unit of a delay count is the period
of the Timebase.
ReTrgCnt 31-bit 1-2147483647 Enables re-trigger to accept multiple
triggers.
1 - 2147483647 for normal operation
See Section 3.4.5: Acquisition with
Re-Triggering
Table 3-4: Counter Parameters and Description