Interface with address decoder for selectively generating first and

Abstract

Interface circuitry for coupling to a microprocessor device. The interface circuitry includes an input for receiving address signal lines and control signal lines generated by the microprocessor device. The interface further includes an address decoder, responsive to the received address signal lines, for determining if a microprocessor-generated memory access is directed to a private memory, accessible only by the microprocessor device, or to a shared memory that is accessible by a plurality of microprocessor devices. Responsive to the address decoder, the interface circuitry provides first address signal lines and first control signal lines to the private memory in response to the microprocessor device generating a memory access to the private memory. Also responsive to the address decoder, the interface circuitry provides second address signal lines and second control signal lines for coupling to the shared memory in response to the microprocessor device generating a memory access to the shared memory. The interface circuitry further includes interrupt control circuitry, inter-processor interrupt circuitry, DMA circuitry, a serial bus interface, and also provides a plurality of miscellaneous functions for the microprocessor.