Timing of the TCC inputs using the gap

Timing of the TCC inputs using the gap flag method

The objective • To align the Trigger FE data into the smallest possible time interval at the input of the TCC

Fixed parameters • FE to TCC fiber lengths

Free parameters • CCS DELAY – 3708 corresponds to signals read out with 0 ns – Granularity: 25/24 ns • But changes > 25 ns => same phase for trigger links (and different pipeline depth for readout) • TCC input clock flip – Moves data-latching edge – Granularity: 0 ns or +12. 5 ns • TCC input pipeline depth – Selects which datum to pick – Granularity: 1 BX – Counter is reset with Resynch BGo • But phase between BGo and clock may differ

Algorithm – step 0 • Have a configuration where All inputs are OK N-1 N All N+1 N+2

Algorithm – step 1 • Invert the phases of All inputs • Identify Very Early inputs N-1 N Very Early OK N+1 N+2

Algorithm – step 2 • Invert the phase for Very Early inputs • Check that all is OK N-1 N Very Early OK N+1 N+2

Algorithm – step 3 • Change the CCS DELAY to +6 (1/4 BX) • Identify the Early inputs N-1 N Ear ly OK N+1 N+2

Algorithm – step 4 • Flip the phase of the Early inputs • Change the CCS DELAY to 0 • Identify Earlier N-1 N Ear lier Ear ly OK OK N+1 N+2

Algorithm – step 5 • Delay the Early 1 inputs • Check all is OK N-1 N Ear lier OK OK N+1 N+2

Algorithm – step 6 • Change the CCS DELAY to +4 • Check all is OK N-1 N OK N+1 N+2

Algorithm – step 7 • Change the CCS DELAY to -4 • Check all is OK N-1 N N+1 OK N+2