High performance cascadable simplex switch
First Claim
1. A switching device for a data communications system, comprising:
- a first simplex serial crossbar switch including a plurality of first I/O ports each of which is adapted to be connected to either (i) a communications subsystem which passes data and control messages to other communications subsystems via said first simplex serial crossbar switch or (ii) one of a plurality of second I/O ports on a second simplex serial crossbar switch;
each of said plurality of first I/O ports having programmable latches for alternatively programming each of said first I/O ports to be connected to either (i) a communications subsystem, wherein a single first I/O port is connected to a single subsystem and said single first I/O port manages both data and control messages sent to and from the connected single subsystem, or (ii) one of said plurality of second I/O ports on said second simplex switch, and wherein one of said pair of second simplex switch, and wherein one of said pair of first I/O ports manages the transfer of data and the other of said pair of first I/O ports manages the transfer of control messages.
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Accused Products
Abstract
A serial simplex switch design is provided which includes I/O ports each of which is configurable specifically for attachment to a data communications subsystem or, alternatively, for cascaded connection to a similarly configured I/O port on another switch. The switch provides a packet routing function including input and output buffers for each of its I/O ports wherein packets of control messages sent by one subsystem are temporarily stored prior to being delivered to the appropriate destination subsystem. When configured to be directly attached to a subsystem, the I/O ports separate control messages from incoming integrated data and control message strings. In a cascade configuration, however, a mechanism is provided wherein data and control messages are separated into two physical paths to eliminate the delays associated with integrated data and control message flow through the cascaded I/O port. Each I/O port is configurable to either of these methods of operation by means of programmable latches associated with the I/O port.
30 Citations
12 Claims
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1. A switching device for a data communications system, comprising:
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a first simplex serial crossbar switch including a plurality of first I/O ports each of which is adapted to be connected to either (i) a communications subsystem which passes data and control messages to other communications subsystems via said first simplex serial crossbar switch or (ii) one of a plurality of second I/O ports on a second simplex serial crossbar switch; each of said plurality of first I/O ports having programmable latches for alternatively programming each of said first I/O ports to be connected to either (i) a communications subsystem, wherein a single first I/O port is connected to a single subsystem and said single first I/O port manages both data and control messages sent to and from the connected single subsystem, or (ii) one of said plurality of second I/O ports on said second simplex switch, and wherein one of said pair of second simplex switch, and wherein one of said pair of first I/O ports manages the transfer of data and the other of said pair of first I/O ports manages the transfer of control messages. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A data communications system comprising:
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a first simplex serial crossbar switch having a plurality of first I/O ports of which (i) at least one of said plurality of first I/O ports is connected to a communications subsystem which passes data and control messages to other communications subsystems via said first simplex serial crossbar switch, and (ii) at ;
least one of said plurality of first I/O ports is connected to a corresponding one of a plurality of second I/O ports on a second simplex serial crossbar switch, said second simplex serial crossbar switch also provided with at least one second I/O port which is connected to a communications subsystem which passes data and control messages to other communications subsystems via the second simplex serial crossbar switch;each of said plurality of first I/O ports on said first serial simplex switch having programmable latches for alternatively programming each of said first I/O ports to be connected to either (i) a communications subsystem, wherein a single first I/O port is connected to a single subsystem and said single first I/O port manages both data and control messages sent to and from the connected single subsystem, or (ii) one of said plurality of second I/O ports on said second simplex switch, wherein a pair of first I/O ports on said first switch are connected to a pair of similarly configured second I/O ports on said second simplex switch, and wherein one of said pair of first I/O ports manages the transfer of data and the other of said pair of first I/O ports manages the transfer of control messages. - View Dependent Claims (8, 9, 10, 11, 12)
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Specification