There are two timers that govern the operation of the retransmission logic in the RX:
- timer1 (Short Timer), configured with the input
CTL_RX_RETRANS_TIMER1 - timer2 (Long Timer), configured with the input
CTL_RX_RETRANS_TIMER2
These timers are configured in terms of Interlaken words that are received during the desired period. For example, assume a configuration of 12 lanes at 5 Gb/s. Each Interlaken word received represents a period of:
- = (67 × 200 ps) / 12
- = 1.12 ns
Therefore to program a timer with a period of 224 ns, it should be configured with a value of 200.
There are two ways to use the timers.