A frame synchronization signal (FrameSync) can be sent through the back channel using any of the back channel GPIOs. The signal can be generated in two different methods. The first option offers sending the external FrameSync using one of the available GPIO pins on the TDES954 and mapping that GPIO to a back channel GPIO on one or two of the V³Link ports.

The second option is to have the TDES954 internally generate a FrameSync signal to send through the back channel GPIO to one or two of the attached Serializers.

FrameSync signaling is synchronous on each of the two back channels. Thus, the FrameSync signal arrives at both of the serializers with limited skew.