CMOS multiport general purpose register

摘要

A general purpose register including two input ports and two output ports, each port being addressed by an independent addressing circuit. The general purpose register includes a number of internal registers, and the provision of four independent addresses enables data to be written into two internal registers while data is being read out of two internal registers. The general purpose register also includes circuitry for transferring data from the input ports directly to the output ports without entering the data into the internal registers. Interchanging of bytes of data input words is also accomplished by the general purpose register. The internal registers, the four independent addressing circuits, the data transferring circuitry and additional undedicated circuitry are integrated into a single chip.