The receive block implements the frame alignment state diagram illustrated in IEEE 802.3 Clause 72, Figure 72-4.
- Frame Lock State Machine
- The frame lock state machine searches for the frame marker, consisting of 16
consecutive 1s followed by 16 consecutive 0s. This functionality is fully
specified in IEEE 802.3 Clause 72, Figure 72-4. When frame lock has been
achieved, the signal
frame_lockis set to a value of TRUE.
- Received Data
- The receiver outputs the control channel with the bit definitions previously
defined in the previous two tables and signal names defined in Port
Descriptions. If a
DME_errorhas occurred during the reception of a particular DME frame, the control channel outputs are not updated but retain the value of the last received good DME frame and are updated when the next good DME frame is received.