Communication multiplexer module

摘要

A communications multiplexer module (CMM) used to provide an interface between a plurality of line adapters and a host computer. A control memory is provided for storing control words, one word for each adapter. A scanner scans the adapters and at the same time addresses the memory to read out the control word associated with that adapter. The control word contains a bit or bits for designating whether the multiplexer is to operate in an input or an output mode for that adapter. Data bits are received from the line adapters serial by bits are assembled in an assembly/disassembly area of the control word. After each character is assembled it is transferred to the host computer interface. Common multiplexed circuitry is provided for performing parity checking, longitudinal redundancy checking and cyclic redundancy checking of messages.