International Business Machines Corporation

Michael R Marr

John C Pescatore

Ronald J Cooper

Mario A Marsico

Gilbert S Burrus, Jr

Paul D Sullivan

Bus interconnection between the system busses of a multi-port communications controller and the busses of one or more multi-port adapters is facilitated with a new architecture for providing an interconnection controller. A programmably adjustable adapter and port interface controller is combined via a scannerless communications controller with a bus interconnection control logic that handles both DMA and interrupt mode data transfers for a large number of channels. The invention provides an improved apparatus and method for transferring data to or from numerous communication channel devices within a processor based communications system in such a manner that the optimum mode of data transfer may be individually programmed for each channel as system environment conditions demand.

Multiple port service expansion adapter for a communications controller

A multi-port communications controller and variable protocol adapter is described. The adapter utilizes a user programmable pluggable programming cartridge for defining individual communications port data service characteristics. The port data service characteristics are interpreted by a microprocessor which manages the interchange from port to port and to or from memory or a host system. Direct memory access or interrupt driven memory access modes of operation are individually selectable for each individual in bound and out bound communications channel. The communications protocols employed at each port may be of any standard type with the microprocessor in the adapter making the appropriate conversion. Communication speeds can be automatically recognized and matched for each port also. An arbitration processor for both DMA and interrupt driven data transfer services is included as the heart of the communications adapter design to provide the capability of individualized control over each in bound and out bound channel's mode of data transfer service for the optimum mode of operation for each port and type of data service required.

Multiple port communications adapter apparatus

Both DMA access and character interrupt driven access modes of service are provided to multiple communication ports by an integrated arbitration DMA/interrupt controller utilizing its own resident randomly accessible memory. Pipelined logic control architecture for handling service mode adaptations for each individual port and for managing memory accesses to main system memory enables the use of the random access memory with its inherent time delays in a manner that virtually eliminates the effect of any time delay in overall memory access throughput.

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Chapel Hill, NC, United States of America

Michael R Marr