ID:186492 Current placement does not support future use of loopback for the GXB transmitter and receiver pairs specified in the submessage of this message

CAUSE: The specified gigabit transceiver block (GXB) transmitters and receiver pairs are placed in different physical channels and will not support loopback. The submessage(s) of this message lists the GXB transmitter and receiver pairs which will not support loopback.

ACTION: To add loopback later in the design cycle place the specified GXB transmitter and receiver in the same physical channel.