Browse Prior Art Database

Command Execution Performance Enhancement

IP.com Disclosure Number: IPCOM000038556D
Original Publication Date: 1987-Feb-01
Included in the Prior Art Database: 2005-Jan-31
Document File: 2 page(s) / 41K

Publishing Venue

IBM

Related People

Freeman, WA: AUTHOR [+3]

Abstract

A method is described to permit a dual-port communications card to execute commands for one of the ports without reducing the performance of the opposite port. A dual-port communications adapter presents performance problems not encountered in a single-port environment. The IBM RT PC Multi- Protocol Communications Adapter uses an on-card microprocessor to off- load the system processor of most low level tasks. This microprocessor-based design provides wide flexibility in the type of tasks that can be done by the adapter but also increases the performance requirements placed on the microprocessor in servicing both ports simultaneously. The new method provides a method for the microprocessor to execute commands for one of the communication ports without reducing the performance capabilities of the opposite port.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 52% of the total text.

Page 1 of 2

Command Execution Performance Enhancement

A method is described to permit a dual-port communications card to execute commands for one of the ports without reducing the performance of the opposite port. A dual-port communications adapter presents performance problems not encountered in a single-port environment. The IBM RT PC Multi- Protocol Communications Adapter uses an on-card microprocessor to off- load the system processor of most low level tasks. This microprocessor-based design provides wide flexibility in the type of tasks that can be done by the adapter but also increases the performance requirements placed on the microprocessor in servicing both ports simultaneously. The new method provides a method for the microprocessor to execute commands for one of the communication ports without reducing the performance capabilities of the opposite port. The IBM RT PC Multi-Protocol Communications Adapter uses a command type that requires blocks of parametric data to be passed to the adapter for initialization purposes. This data is passed to the adapter via Direct-Memory Access (DMA). The problem normally encountered is that this type of command takes a long time to execute, thereby causing performance problems on the opposite port. This method provides a technique whereby the processor can interleave the execution of a long-type command and the servicing of the opposite port to eliminate transmit underruns and receive overruns. The microprocessor monitors transmit and receive requests from...