Universal interface circuit for microprocessor peripherals

Abstract

A universal interface adaptor circuit (UIAC) for connecting any one of a plurality of either of two general microprocessor types to a peripheral device using the same interface connections to selectively generate and supply either a WRITE ENABLE signal or a READ ENABLE signal to a peripheral device. A first of the two general types of microprocessors is used in multiplexed-bus multiprocessor (MBM) systems and the second of the two general types of microprocessors is used in non-multiplexed-bus microprocessor (NMBM) systems, where the microprocessors used in both the MBM and the NMBM systems each supply three output signals for determining whether the function is a READ or a WRITE function and the time of occurrence of such READ or WRITE function. The UIAC comprises logic array having three input terminals X, Y, and Z for receiving the three output signals from each of the microprocessors employed in either the MBM systems or the NMBM systems. First selected logic elements of the logic array respond to the three output signals received from the MBM type systems to produce a READ ENABLE signal when the signals thereon indicate a READ function and a WRITE ENABLE signal when the signals thereon indicate a WRITE function, and second selected logic elements of the logic array respond to the three output signals received from the NMBM type systems to produce a READ ENABLE signal when the signals thereon indicate a READ function, and to produce a WRITE ENABLE signal when the signals thereon indicate a WRITE function.