Find the best parameters for the cluster masking

Description

The spurious signals upon L1A force us to mask all clusters during N BX, M BX after the L1A. In case it is not done, we send many in-time clusters in the L1 trigger path.

The firmware feature is implemented, but a scan is required to adjust the parameters on a per OptoHybrid basis.

Possible fixes

Scan the cluster masking parameters

The scan sequence is roughly the following:

1. Disable the cluster masking
2. Measure the S-bit rate with the L1A disabled
3. Enable period L1A at the target frequency (100 kHz)
4. Measure the S-bit rate without any masking
5. Scan the masking parameters
   • BEFE.GEM.OH.OH{}.FPGA.TRIG.L1A_MASK.L1A_MASK_DELAY
   • BEFE.GEM.OH.OH{}.FPGA.TRIG.L1A_MASK.L1A_MASK_WIDTH
   • Measure the S-bit rate for each point
   • If designed properly, only the first register has to be scanned while the second one can remain constant. The analysis routine should be able to derive both parameters.

Analyze the scan output to derive the best parameters

Analyze the output of the scan to derive the optimal values for BEFE.GEM.OH.OH{}.FPGA.TRIG.L1A_MASK.L1A_MASK_DELAY and BEFE.GEM.OH.OH{}.FPGA.TRIG.L1A_MASK.L1A_MASK_WIDTH. It is important to take into account the normal fluctuation in the S-bit rate in order to reduce the masking window as much as possible.