Browse Prior Art Database

Micro Channel Streaming Data Request Control

IP.com Disclosure Number: IPCOM000108636D
Original Publication Date: 1992-Jun-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 1 page(s) / 32K

Publishing Venue

IBM

Related People

Arimilli, RK: AUTHOR [+3]

Abstract

Disclosed is a design of the Streaming Data Request lines on the Micro Channel* to maximize performance with minimal logic cost.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

Micro Channel Streaming Data Request Control

       Disclosed is a design of the Streaming Data Request lines
on the Micro Channel* to maximize performance with minimal logic
cost.

      Streaming Data is a high performance protocol defined by the
Micro Channel Architecture.  Protocols defined by the Micro Channel
allow master and slave to establish the Streaming Data mode of data
transfer.  The signals '-SDR(0,1)' are used by the slave to indicate
to the master that it is Streaming Data capable and the transfer
rate. These signals are also used by the slave to terminate the
Streaming Data protocol.

      The I/O Channel Controller pulls 'CD CHRDY' inactive on 64-byte
boundaries.  The '-SDR(0,1)' signals are pulled active if the address
is on a four-byte boundary instead of 64-byte boundary to maximize
performance.  The '-SDR(0,1)' signals are not activated if the
address is less than two times the width of the master from the
64-byte boundary (e.g., two-byte master/less than four bytes,
four-byte master/less than eight bytes).  If the '-SDR(0,1)' lines
were activated, then 'CD CHRDY' would need to be deactivated during
the Streaming Data protocol.  This would have required the I/O
Channel Controller to implement another set of protocols with
extremely tight timings.
*  Trademark of IBM Corp.