Technique for automatically adapting a peripheral integrated circuit for

Abstract

By monitoring various combinations of control signals generated by a microprocessor in a computer system in the first operational cycles after it is reset, a peripheral circuit sets itself to respond appropriately to control signals from the microprocessor according to any of several different protocols. For example, an instruction from the microprocessor to write to or read from the peripheral circuit is implemented over two control lines with one of several possible protocols. The circuit determines which protocol is being used each time the system is initialized and thereafter knows when a read or write operation is being performed. Another example is the different wait or acknowledge protocols that various microprocessors use. The peripheral circuit can thus be used with a variety of microprocessors without having to provide sets of pins dedicated to each signal protocol used by available microprocessors, and without the necessity to load a configuration register in the peripheral circuit by the microprocessor as part of the initialization process.