Hi Folks,
I've been mulling over what appears to me to be a point of ambiguity in 802.3cd, & I'd like to solicit some feedback from other task force members about what "standards-compliant" behavior is expected to be in this case. The scenario involves the link training process, and specifically is related to Figure 136–9—Coefficient update state diagram, when the local side in the NEW_REQUEST state. If a subsequent training frame receiver from the remote side specifies coef_req=hold AND coef_sel^=k, the behavior of the Coefficient Update FSM would be to first transition to WAIT (with new coef_sts output by the ENCODE_STS function), & thereafter immediately transition to NEW_INDEX (due to coef_sel^=k, & with the new k value output by the ENCODE_STS function). However, since there is no specified interlock between FSM transitions (with resulting status updates) & training frame transmission, is it possible the ENCODE_STS update captured in the WAIT state will not be transmitted, but instead be overwritten by the ENCODE_STS update captured in the NEW_INDEX state? Or is it expected the "intermediate" ENCODE_STS update during WAIT will appear in at least one transmitted frame, followed by the "final" ENCODE_STS update in NEW_INDEX?
Seems to me the intended behavior of the FSM in this case would be to bypass the "intermediate" status value, & instead transition directly from NEW_REQUEST to NEW_INDEX and transmit only the "final" status value. If this is the case, seems an update to the Coefficient Update FSM is in order. Thoughts...?
Thanks & Regards,