Acqiris SA220P - Page 56

4.4 Thresholding (Zero-Suppress - ZS1 option)
56 Acqiris SA220P User's Manual
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Start sample position Block index Reserved
0x04
Table 4.5 - Start gate marker fields.
Where:
- Block Index returns the position of the start gate with a resolution of 8 samples.
- Start Sample position returns the position of the start gate within Block Index with one
sample resolution (range is [0 .. 7]).
The start gate position in number of samples is then given by:
(Block Index - 1) * ProcessingBlockSize + Start Sample position.
Stop gate marker
The stop gate markers are encoded in 64-bit, as described below.
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Stop sample position Block index Reserved
0x05
Table 4.6 - Stop gate marker fields.
Where:
- Block Index returns the position of the stop gate with a resolution of 8 samples.
- Stop Sample position returns the position of the one-past last sample of the gate within
Block Index with one sample resolution (range is [0 .. ProcessingBlockSize – 1]).
The stop gate position in number of samples is given by:
(Block Index - 1) * ProcessingBlockSize – (ProcessingBlockSize – Stop
Sample position)
With ProcessingBlockSize = 8 for the SA220P.
Stop-record marker
A stop-record indicates the end of the record (end of the gate detection window).
The stop-record markers are encoded in 64-bits, as described below.
63 56 55 24 23 8 7 0
Stop sample position Block index Reserved
0x0A
Table 4.7 - Stop-record marker fields.
Where:
- Block Index returns the position of the stop-record with a resolution of 8 samples.
- Stop Sample position returns the position of the last sample within Block Index with one
sample resolution.
The Stop Record position in number of samples is given by:
(Block Index - 1) * ProcessingBlockSize – (ProcessingBlockSize – Stop
Sample position - 1)
With ProcessingBlockSize = 8 for the SA220P.