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Data Channel With Computing Engine Operated by Microcode for Different Operating Modes And Overlapped by Separate Hardware for Functions Common to All Modes

IP.com Disclosure Number: IPCOM000060106D
Original Publication Date: 1986-Feb-01
Included in the Prior Art Database: 2005-Mar-08
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Casper, DF: AUTHOR

Abstract

A data channel has a computing engine that executes microprograms and a control memory that can be loaded with a selected microprogram to operate the channel in one of several modes. different microprograms the channel can operate as a block, byte, or burst multiplexer, and it can operate with a central processor having a particular set of I/O instructions and a particular format for control blocks. Alternatively it can operate partly with a central processor and partly with a separate I/O processor (IOP) that handles some of the operations otherwise performed by a central processor. The channel also has hardware that performs operations that are common to all modes and/or can be overlapped with the execution of a microprogram. The channel hardware is a small processor suitably programmed for the hardware operations.

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Data Channel With Computing Engine Operated by Microcode for Different Operating Modes And Overlapped by Separate Hardware for Functions Common to All Modes

A data channel has a computing engine that executes microprograms and a control memory that can be loaded with a selected microprogram to operate the channel in one of several modes. different microprograms the channel can operate as a block, byte, or burst multiplexer, and it can operate with a central processor having a particular set of I/O instructions and a particular format for control blocks. Alternatively it can operate partly with a central processor and partly with a separate I/O processor (IOP) that handles some of the operations otherwise performed by a central processor. The channel also has hardware that performs operations that are common to all modes and/or can be overlapped with the execution of a microprogram. The channel hardware is a small processor suitably programmed for the hardware operations. The operations of the microprogrammed engine and the hardware are synchronized by a set of latches.

The engine has a local store for a unit control word for each device and a control unit control word for each control unit. In multiplexing, the engine uses the control word for one device for transferring one or more bytes and then uses another control word for another device for an independent data transfer. The engine similarly uses the control unit control words for operations with different control units. The local store also...