A single-chip integrated circuit, sometimes called a controller, controls
operation of a transceiver having a laser transmitter and a photodiode
receiver. The controller includes memory for storing information related
to the transceiver, and 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 locations within the
memory. Comparison logic compares one or more of these digital values
with predetermined setpoints, generates flag values based on the
comparisons, and stores the flag values in predefined locations within
the memory. Control circuitry in the controller shuts off the laser
transmitter in response to comparisons of signals with predetermined
setpoints that indicate potential eye safety hazards.