Browse Prior Art Database

Asynchronous User Independent Service Channel On a TDM Link

IP.com Disclosure Number: IPCOM000122024D
Original Publication Date: 1991-Oct-01
Included in the Prior Art Database: 2005-Apr-04
Document File: 4 page(s) / 73K

Publishing Venue

IBM

Related People

Badaoui, M: AUTHOR [+5]

Abstract

This article describes an independent service channel on a Time Division Multiplex Link. This concept allows a completely asynchronous access for each device m Multiplexed on a unique slot. This feature has no native addressing or message length limitation. The channel can be used for Read/Write Internal Registers (Reg) or to pass asynchronous messages for device detected error signalling. I CHANNEL ADDRESSING CONCEPT

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Asynchronous User Independent Service Channel On a TDM Link

      This article describes an independent service channel on
a Time Division Multiplex Link. This concept allows a completely
asynchronous access for each device m Multiplexed on a unique slot.
This feature has no native addressing or message length limitation.
The channel can be used for Read/Write Internal Registers (Reg) or to
pass asynchronous messages for device detected error signalling.
I CHANNEL ADDRESSING CONCEPT

      Table 1 below shows the independent channel addressing for
devices attached to a TDM Link. D/C means DATA/CONTROL.
I CHANNEL STRUCTURE

      As shown in Table 2 the I Channel structure is as follow:
EXAMPLE OF APPLICATION

      As shown in Tables 3, 4 and 5, the I Channel can be used
as Command/Response Service Channel between Master and Slave devices.
The outbound path describes the channel mapping from Master to Slave
Device, and the inbound path describes the channel mapping from Slave
to Master device.
OUTBOUND MAPPING
      -  '10' Sequence is I message delimiter
      -  T0/T1 are Command type bits
      -  A0... A10 is address field
      -  AP is address parity
      -  D0... D7 is data field (irrelevant for a read)
      -  DP is data parity
INBOUND MAPPING
      -  '10' Sequence is I message delimiter
      -  T0/T1 are acknowledge bits
      -  D0... DP is data field (irrelevant for a write)
      -  ...