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.