Circuitry for monitoring operation of an optoelectronic device having a
laser transmitter and a photodiode receiver includes analog to digital conversion
circuitry for receiving a plurality of analog signals from the laser transmitter
and photodiode receiver, converting the received analog signals into digital values,
and storing the digital values in predefined memory-mapped locations within the
optoelectronic device. Comparison logic compares one or more of these digital values
with limit values, generates flag values based on the comparisons, and stores the
flag values in predefined locations within the optoelectronic device. An interface
enables a host device to read from and write to host-specified memory mapped locations
within the optoelectronic device.