METHOD OF SYNCHRONIZING A PAIR OF CENTRAL PROCESSOR UNITS FOR DUPLEX LOCK STEP OPERATION

A method of synchronizing a pair of substantially identical processors for substantial lock-step operation is disclosed. One of the processors is operational, executing an instruction stream from a memory element exclusive to that processor; the other processor is in a wait state. The method involves copying the instruction and data content of the memory of operating processor to the memory of the welting processor in a manner that stores the transferred instructions and data in the memory of the waiting processor at locations that correspond to where the instructions and data are located in the memory of the operating processor. Thereafter, the operating processor will periodically send selected ones of the instructions and data to the waiting processor.