ROC-EB Synchronization.(preliminary)
- One of the ROCs is a master. It is equipped with VME output register. All other ROCs equipped with VME input register. Master ROC distribute event number and, possibly, event type via cable connection between registers.
- All ROCs receives L2 trigger and starts conversion.
- Master ROC waits until it has a room for N events (N should be greater than the maximum event FIFO depth in the system).
- Master ROC increments event number and distribute it to other ROCs,
- Other ROCs, before putting subevent into the CODA buffer should wait for the increment of the event number.
- ROC should put the subevent into the CODA buffer after detecting this increment, if it has no data to send, it should put an event header.
- If ROC has a full token, it sends it to the EB.
- If EB detects a mismatch between subevents from different ROCs, it forces the master ROC to hold the event number for a time interval, long enough to free all FIFOs and mark next event type as a sync.