An apparatus includes a receiver, an error detection unit, and an acknowledgement unit. The receiver may receive frames of data from a transmitter unit of a second apparatus via a first communication path. The error detection unit may detect data errors in the frames of data received via the first communication path. The acknowledgment unit may maintain an acknowledgement indicator indicative of whether frames received by the apparatus are error free. In response to the error detection unit detecting an error, the acknowledgement unit may indicate an error condition exists by freezing a value of the acknowledgement indicator, or alternatively the acknowledgement unit may set a current value of the acknowledgement indicator to a predetermined error value. Further, the apparatus may successively convey values of the acknowledgement indicator to the second apparatus via a second communication path while the apparatus is receiving frames.