Browse Prior Art Database

Split Local Store Buffer

IP.com Disclosure Number: IPCOM000092165D
Original Publication Date: 1968-Oct-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 39K

Publishing Venue

IBM

Related People

Anderson, LB: AUTHOR [+2]

Abstract

A local store in this channel is used for buffering data and is split into two independently operating portions A and B, This allows the channel to operate with a relatively slow main storage while, at the same time, providing the ability to transfer data to and from I/O devices at high speeds.

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Split Local Store Buffer

A local store in this channel is used for buffering data and is split into two independently operating portions A and B, This allows the channel to operate with a relatively slow main storage while, at the same time, providing the ability to transfer data to and from I/O devices at high speeds.

A local store is usually unable to receive and transmit data simultaneously. However, this channel must be able to continuously send or receive a byte of data to or from I/O devices 10. Without interrupting this flow, the channel must be able to send or receive sixteen bytes of data to or from main storage. This is realized by splitting the local storage into two portions A and B which can transfer data between each other and can also operate concurrently. Thus, while portion A is involved with transfers between main storage, portion B is free to communicate with the I/O devices. Storage counter 12 provides an address which points to the location of a word of data 1, 2, 3, and 4 in storage A. Transfer counter 14 provides addressing which simultaneously addresses a word of data in storage A while simultaneously addressing a corresponding word of data in storage B. Thus, an entire word can be transferred between storages A and B. Interface counter 16 points to a byte of data 1, or 2, or 3, etc., in storage
B. Registers 18 and 20 each store one byte of data coming from or going to I/O devices 10. Sixteen-byte register 22 is provided for temporarily storing data to be transferred to the main storage.

In a typical operation, a byte of data is read from I/O Bus In and stored in register 18. Initially, interface counter 16 points to byte position 1 in storage B. The first byte of information is therefore stored in this position, th...