The TX Interface includes the parallel clock TXUSRCLK. The required rate for TXUSRCLK depends on the interface width of the GTME5_QUAD primitive and the TX line rate of the GTM transmitter. The following equation shows how to calculate the required rate for TXUSRCLK for all cases.
TXUSRCLK is the internal synchronization clock for all signals into the TX side of the GTM transceiver. Most signals into the TX side of the GTM transceiver are sampled on the positive edge of TXUSRCLK.