RX Register Mode (Design Considerations)
When the RX is configured in register mode, the phase compensation FIFO is bypassed. This
bypass introduces clock skew between the transceiver's RXD signal and
the core logic clocked by the transceiver recovered clock
PMA_DIRECT_RX_CLK. To address this clock skew you must insert a bus
of negative edge registers on the RXD path to address hold
violations.