The input CTL_RX_RETRANS_ACK should be connected to one of the
tx_update outputs of the TX Out-of-Band Flow Control module. The
tx_update signal is used to clear the
STAT_RX_RETRANS_REQ signal so the next message sent by the TX
Out-of-Band Flow Control module will not have the request bit set which is in keeping
with the requirement in section 2.2.1 of the Interlaken Retransmit
Extension Protocol Definition, Revision 1.2, June 28, 2012 which
states:
"The bit in the calendar must be deasserted, set to Xoff, before another retransmit request can be signaled."
The output STAT_RX_RETRANS_REQ should be connected to one of the
tx_fc inputs of the TX Out-of-Band Flow Control module that
corresponds to the selected tx_update signal. The length of the
calendar affects the request-to-discontinuity latency. It might be desirable to have a
separate Out-of-Band Flow Control interface for retransmission requests.