Browse Prior Art Database

Slave SDLC Processor

IP.com Disclosure Number: IPCOM000050620D
Original Publication Date: 1982-Nov-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 2 page(s) / 39K

Publishing Venue

IBM

Related People

Nowell, JT: AUTHOR [+3]

Abstract

An SDLC (Synchronous Data Link Control) secondary station must respond to frequent non-productive polls issued by the primary station. This constant activity uses processor bandwidth and reduces the system performance in running a user's application. The figure illustrates how a slave processor can be used to control an SDLC secondary link.

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Slave SDLC Processor

An SDLC (Synchronous Data Link Control) secondary station must respond to frequent non-productive polls issued by the primary station. This constant activity uses processor bandwidth and reduces the system performance in running a user's application. The figure illustrates how a slave processor can be used to control an SDLC secondary link.

The Slave Link Microprocessor 4 has the ability to run self-diagnostics upon power-up after which the Main System Microprocessor 1 verifies communications to the Slave Link Microprocessor 4 via Channel 3. Transmit, Receive, Auto Poll Response and Diagnostic commands can be sent to the Slave Link Microprocessor 4.

When the Main System Microprocessor 1 is ready to use the SDLC Link 10, the microprocessor issues a Transmit or Receive command. At the completion of the transmitted or received frame, the Main System Micro processor 1 is notified by the Slave Link Microprocessor 4 that it can proceed with the next command. When in Auto Poll Response Mode, the Slave Link Microprocessor 4 has the ability to automatically respond to polls from the primary SDLC station without the Main System Microprocessor 1 intervening. The Main System Microprocessor 1 can thereby run an application program without the burdensome task of frequent poll responses. Diagnostic Commands cause the Slave Link Microprocessor 4 to exercise the hardware by wrapping data either through the SDLC Controller Module 7 or out through the Link Driv...