Appendix B: Registers
151
L30 Extra pole included for generalizing the filter.
DPCFG (Datapath configuration)
10 Single order section architecture When this is enabled the filter is changed
from a 4th order filter to a 3rd order filter.
11 Signed coefficients Enables signed Pole/Zero coefficients
B.2.3 Baseline Correction 1
These are the configuration settings for the various filtering capabilities of the first
baseline correction filters.
FPD (Fixed pedestal) Each channel has a baseline value which usually is desirable to remove so that the signal is sitting at zero instead of at an offset from zero.
The value is two’s complement with two extra bits of precision.
VPD (Variable pedestal) The current baseline calculated by the variable pedestal
filter.
DPCFG (Datapath configuration)
4 Invert input Negates the input to the baseline correction 1 filter.
5 Invert output Negates the output value of the pedestal memory.
BC1THRL (Threshold low) Sets the threshold below the current value of the
VPD for when the VPD should not update its value. If BC1CFG[6] is enabled
then this threshold is an absolute threshold instead of being relative to the current
VPD value.
BC1THRH (Threshold high) Sets the threshold above the current value of the
VPD for when the VPD should not update its value. If BC1CFG[6] is enabled
then this threshold is an absolute threshold instead of being relative to the current
VPD value.
BC1CFG (Baseline correction 1 configuration)
3:0 Taps Sets the number of taps of the VPD filter.
4 Auto reset When the signal has been outside the acceptance thresholds for a
specified time given by BC1RSTCNT the filter will reset and open up the
thresholds so that it can regain the correct baseline and avoid getting stuck.
If this bit is set high it will open the thresholds for 31 cycles, and if it is low
it will open them for 15 cycles.
5 VPD always on The VPD filter can be set to only run when outside of a time
window or it can be forced to run all the time when this setting is enabled. If
running in continuous mode and one wants to use the VPD then this needs
to be enabled.
151
L30 Extra pole included for generalizing the filter.
DPCFG (Datapath configuration)
10 Single order section architecture When this is enabled the filter is changed
from a 4th order filter to a 3rd order filter.
11 Signed coefficients Enables signed Pole/Zero coefficients
B.2.3 Baseline Correction 1
These are the configuration settings for the various filtering capabilities of the first
baseline correction filters.
FPD (Fixed pedestal) Each channel has a baseline value which usually is desirable to remove so that the signal is sitting at zero instead of at an offset from zero.
The value is two’s complement with two extra bits of precision.
VPD (Variable pedestal) The current baseline calculated by the variable pedestal
filter.
DPCFG (Datapath configuration)
4 Invert input Negates the input to the baseline correction 1 filter.
5 Invert output Negates the output value of the pedestal memory.
BC1THRL (Threshold low) Sets the threshold below the current value of the
VPD for when the VPD should not update its value. If BC1CFG[6] is enabled
then this threshold is an absolute threshold instead of being relative to the current
VPD value.
BC1THRH (Threshold high) Sets the threshold above the current value of the
VPD for when the VPD should not update its value. If BC1CFG[6] is enabled
then this threshold is an absolute threshold instead of being relative to the current
VPD value.
BC1CFG (Baseline correction 1 configuration)
3:0 Taps Sets the number of taps of the VPD filter.
4 Auto reset When the signal has been outside the acceptance thresholds for a
specified time given by BC1RSTCNT the filter will reset and open up the
thresholds so that it can regain the correct baseline and avoid getting stuck.
If this bit is set high it will open the thresholds for 31 cycles, and if it is low
it will open them for 15 cycles.
5 VPD always on The VPD filter can be set to only run when outside of a time
window or it can be forced to run all the time when this setting is enabled. If
running in continuous mode and one wants to use the VPD then this needs
to be enabled.