A dual processor framer includes a receiver and a transmitter which share
common circuitry and/or code. Separate direct memory access controllers
may be used for each of the receiver and transmitter. Processing is
distributed over two or more processors. One processor may be a lower
power processor while another processor may be a higher power processor.
At least one of the two or more processors may be programmable or
reconfigurable. The transceiver is configured to provide internal loop
back self testing at various points in the processing. Timing within the
transceiver may be established almost entirely by a single clock domain.