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Appendix B: Registers
BC3BSL (Baseline) The baseline as calculated by the BC3 filter.
BC3SLD (Slope down) The rate at which the average changes in the downward
direction when the signal is below the current average. The value is given with
0.25 bits precision.
BC3SLU (Slope up) The rate at which the average changes in the upward direction when the signal is above the current average. The value is given with 0.25
bits precision.
B.2.6 Zero Suppression
The following registers set the thresholds, offsets and other configuration options for
running with zero suppression.
ZSTHR (Zero suppression threshold) Signals below this value will be suppressed and not included in the data stream. The value is given with 0.25 bits
precision. Setting this value to zero effectively disables zero suppression as long
as no filters are enabled which can bring the sample value below zero.
ZSOFF (Zero suppression offset) Since data is transmitted as 10 bits unsigned,
there is a necessity to truncate the data to only positive values. To avoid losing
information, like the tale of pulses that can pass below the average, it is possible to add an offset to all values before truncation. As this happens before the
zero suppression threshold decision, any offset added here needs to be taken into
account when setting the threshold.
ZSCFG (Zero suppression configuration)
1:0 A glitch filtering setting to remove spurious signals above the zero-suppression
threshold. With this set to 4 , the pulses that are 3 samples or shorter will be
removed. If it is 3, then pulses that are 2 samples or shorter will be removed.
With this set to 2, then single samples above the threshold will be removed.
Setting it to 0 will accept all pulses.
4:2 Samples before pulse starts Sets the number of samples before the signal
passes above the threshold that should be included.
6:5 Samples after pulse ends Sets the number of samples after the signal has
passed below the threshold that should also be included.
8 Raw samples Enables sending of samples that have not been modified by the
BC2 or BC3 filter, but the zero suppression threshold decision is still done
on the filtered baseline.
Appendix B: Registers
BC3BSL (Baseline) The baseline as calculated by the BC3 filter.
BC3SLD (Slope down) The rate at which the average changes in the downward
direction when the signal is below the current average. The value is given with
0.25 bits precision.
BC3SLU (Slope up) The rate at which the average changes in the upward direction when the signal is above the current average. The value is given with 0.25
bits precision.
B.2.6 Zero Suppression
The following registers set the thresholds, offsets and other configuration options for
running with zero suppression.
ZSTHR (Zero suppression threshold) Signals below this value will be suppressed and not included in the data stream. The value is given with 0.25 bits
precision. Setting this value to zero effectively disables zero suppression as long
as no filters are enabled which can bring the sample value below zero.
ZSOFF (Zero suppression offset) Since data is transmitted as 10 bits unsigned,
there is a necessity to truncate the data to only positive values. To avoid losing
information, like the tale of pulses that can pass below the average, it is possible to add an offset to all values before truncation. As this happens before the
zero suppression threshold decision, any offset added here needs to be taken into
account when setting the threshold.
ZSCFG (Zero suppression configuration)
1:0 A glitch filtering setting to remove spurious signals above the zero-suppression
threshold. With this set to 4 , the pulses that are 3 samples or shorter will be
removed. If it is 3, then pulses that are 2 samples or shorter will be removed.
With this set to 2, then single samples above the threshold will be removed.
Setting it to 0 will accept all pulses.
4:2 Samples before pulse starts Sets the number of samples before the signal
passes above the threshold that should be included.
6:5 Samples after pulse ends Sets the number of samples after the signal has
passed below the threshold that should also be included.
8 Raw samples Enables sending of samples that have not been modified by the
BC2 or BC3 filter, but the zero suppression threshold decision is still done
on the filtered baseline.