US Patent 7787766 Fault sensor for a laser driver circuit

An apparatus and method is provided for sensing which faults have occurred in a laser control system, as well as trapping and identifying the first fault occurrence. The apparatus includes an integrated circuit in which a mask register is set by means of a micro-controller or a host system to select which fault sources are to be recorded. A status bit register in which the fault indications are stored can also be interrogated by the micro-controller or a host system. A settable first fault status register determines whether every fault or only the first fault gets recorded.