Communication between two microprocessors through common memory

Advances in integration have enabled the design of dual microprocessor systems on a single board for extra processing power. The problems of interfacing these processors are discussed and reasons for preferring shared memory communications rather than I/O are outlined. A system using two 6809 microprocessors is described with the technical problems that were encountered or anticipated in its design. Software developed uses the ‘producer consumer’ analogy and three solutions are demonstrated.