Browse Prior Art Database

Automatic Monitoring of Received Asynchronous Communications Data for Line Control

IP.com Disclosure Number: IPCOM000100872D
Original Publication Date: 1990-Jun-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 2 page(s) / 58K

Publishing Venue

IBM

Related People

Krantz, JI: AUTHOR [+4]

Abstract

A technique is described whereby received data from an asynchronous communications channel is automatically monitored and controlled so as to relieve a processor of having to monitor data byte-by-byte in real- time. Described is the use of character compare registers which control the functions of asynchronous communications circuitry.

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This is the abbreviated version, containing approximately 56% of the total text.

Automatic Monitoring of Received Asynchronous Communications Data for Line Control

       A technique is described whereby received data from an
asynchronous communications channel is automatically monitored and
controlled so as to relieve a processor of having to monitor data
byte-by-byte in real- time. Described is the use of character compare
registers which control the functions of asynchronous communications
circuitry.

      In prior art, automatic monitoring of asynchronous
communications required extensive attention from a processor to
perform the monitoring of the data.  The concept described herein
reduces the amount of monitoring required by relieving the processor
from having to monitor the incoming data in real-time.  This is
particularly important when high speed data rates are employed, such
as 256K bits/second, and in multi-user systems with multiple
terminals attached through asynchronous communications channels.

      The concept utilizes several character compare registers (CCRs)
and several character compare function registers (CCFRs) imbedded in
asynchronous communications circuitry.  Each CCR can be loaded with
any character of the user's choice.  As characters are received over
the asynchronous communications channel, the characters are
simultaneously compared with all CCRs.  If any match is found, the
function is performed in the corresponding CCFR.

      The CCFR has four functions that can be enabled in any
combination:
  ...