Browse Prior Art Database

First In First Out Queue Management of Connect Requests in a Simplex Switch

IP.com Disclosure Number: IPCOM000105775D
Original Publication Date: 1993-Sep-01
Included in the Prior Art Database: 2005-Mar-20
Document File: 2 page(s) / 73K

Publishing Venue

IBM

Related People

Cazzolla, JJ: AUTHOR [+5]

Abstract

Disclosed is the use, at a port of a simplex switch, of a first register to indicate whether a particular subsystem has an entry in a connect request FIFO (First-In, First-Out) queue, and of a second register to indicate whether the entry is valid, being active, or invalid, having been dequeued.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

First In First Out Queue Management of Connect Requests in a Simplex Switch

      Disclosed is the use, at a port of a simplex switch, of a first
register to indicate whether a particular subsystem has an entry in a
connect request FIFO (First-In, First-Out) queue, and of a second
register to indicate whether the entry is valid, being active, or
invalid, having been dequeued.

      A simplex-mode serial crossbar switch interconnecting a number
of subsystems is designed to support connect request queuing.  When a
calling subsystem issues a connect request frame to the switch, and
when the switch determines that the called subsystem is busy, being
connected to another calling subsystem, the switch stores the connect
request in a FIFO queue associated with the called subsystem.  Once
the current connection is disconnected, the next connect request in
this queue is processed by the switch.  The switch provides a connect
request acknowl edge message frame to the calling subsystem, and a
new connection is made.

      This switch is also designed to support connect request
dequeuing after a calling subsystem connect request has been queued,
for example, when a new, higher priority event occurs within the
calling subsystem, requiring connection to another subsystem.  The
subsystem issues a dequeue request message frame to the switch, which
removes the connect request and responds with a dequeue request
acknowledge message frame.

      The Figure provides an example of the registers associated with
a single port of a 16-port, simplex serial crossbar switch.  Since
each port may be called by any or all of the other 15 ports, FIFO
queue 1 can accommodate up to 15 connect requests.  In this example,
FIFO...