Browse Prior Art Database

Master Streaming Data Boundary Optimizations On the Micro Channel

IP.com Disclosure Number: IPCOM000120637D
Original Publication Date: 1991-May-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 1 page(s) / 41K

Publishing Venue

IBM

Related People

Arimilli, RK: AUTHOR [+4]

Abstract

The Micro Channel* bus contains a high-speed data transfer protocol called Streaming Data. This protocol allows devices to transfer sequential blocks of data by driving an address cycle followed by many compressed data cycles. Unlike standard cycles, boundary conditions during Streaming Data cause many Masters to introduce many DEAD cycles on the Micro Channel to enter/exit Streaming.

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Master Streaming Data Boundary Optimizations On the Micro Channel

      The Micro Channel* bus contains a high-speed data
transfer protocol called Streaming Data.  This protocol allows
devices to transfer sequential blocks of data by driving an address
cycle followed by many compressed data cycles. Unlike standard
cycles, boundary conditions during Streaming Data cause many Masters
to introduce many DEAD cycles on the Micro Channel to enter/exit
Streaming.

      This introduces a bit of a paradox on the Micro Channel.  If a
device tries to stream a lot of small sequential blocks of data, it
may take longer than if the device performed standard cycles.  To
alleviate this problem and provide higher performance and flexibility
on the Micro Channel, the following design considerations are
disclosed to optimize Master implementations:
   1) Activation of -SD STROBE only if
   [(-PREEMPT=1) or (Burst Control Counter Overflow = 0)]
   AND [[(ADD=00) and (-DS16=0 or -DS32=0) and (Byte Count >= 8)]
   OR [(ADD=00) and (-DS16=0 or -DS32=1) and (Byte Count >= 4)]
   OR [(ADD=00) and (-DS16=1           ) and (Byte Count >= 2)]]
  2) Activation of -SD STROBE falling concurrent with -CMD falling if
READY=1.
  3) Activation of -SD STROBE falling independent of -SDR(0..1).
  4) During deferred Streaming Cycles, activation of -SD STROBE
within 0-50ns of READY rising.
  5) During Master Terminated Sequence, inhibit -S0,1 rising if
READY=0.  Wait for READY...