COMMUNICATION MULTIPLEXER HAVING A VARIABLE PRIORITY SCHEME USING A READ ONLY MEMORY

摘要

A data processing system includes a number of input/output devices coupled to a communication multiplexer which polls the devices in a predetermined order. Apparatus in the communication controller rearranges the polling order to provide highest priority to an input/output device in a transmit mode that is currently operative and to give lowest priority to an input/output device in a receive mode that has just completed its operation.