Priority resolution network for input/output exchange

Claim 2

In combination with a system having a first group of m number of units which can communicate with any one of a second group of n number of units through an m X n cross-point switching matrix by generating a request signal identifying the unit in the first group and an address signal identifying a unit in the second group, apparatus for controlling said switching matrix comprising scanning means for repeatedly identifying in time sequence each of the units in the first group, storage means having a plurality of stages, each stage being adapted to store signals identifying any one of the units of the first group, matrix control gating means having a plurality of separate outputs connected respectively to each cross point in the switching matrix to control the connection at each cross point, register means for storing information in electrically coded form, means synchronized with the scanning means and responsive to the output of the matrix control gating means for storing information in the register means indicating as to each unit of the second group whether the output of the gating means has completed a connection to the particular unit, means coupling the output of the register means to the matrix control gating means, priority means coupled to the output of several of the stages of the storage means and the output of the matrix control gating means for selectively coupling the output of the scanning means and at least one stage of the storage means to the matrix control gating means, the gating means activating a particular output to a cross-point in the matrix in response to the corresponding request signal and address signal from a unit in the first group when the output from the register means indicates the addressed unit of the second group is available and the output of one of the stages or the scanning means identifies the associate unit of the first group.

Claim 3

Apparatus as defined in claim 1 further including means responsive to the output of the gating means for setting the lowest order empty stage in the storage means in response to the output of the scanning means when the output of the gating means indicates a request to a particular address has not been gated whereby the identification of any requesting unit in the first group seeking an unavailable unit in the second group is stored in the storage means in predetermined order.

Claim 4

Apparatus as defined in claim 2 further including means for shifting the contents of the storage means, and means responsive to the output of the matrix control gating means and the contents of the storage means for shifting the contents when a connection is completed to a unit whose identification is stored in the storage means.

Claim 5

Apparatus for selectively completing electrical connections between any one of a first group of electrical signal generating and/or receiving units and any one of a second group of electrical signal generating and/or receiving units, said apparatus comprising means associated with each of the units of the first group for initiating a request signal identifying the associated unit of the first group seeking connection to a unit of the second group and initiating an address signal identifying a particular unit of the second group to which a connection is being requested, cross-point switching means for selectively completing an electrical connection between any of the first group of units and any of the second group of units, and control means responsive to the request signals and address signals from said request and address signal initiating means for operating the cross points of said switching means to complete electrical connections between the requesting units of the first group and the addressed units of the second group, said control means including scanning means successively identifying each of the units in the first group in time sequence at the output thereof, register means coupled to the output of the control means for generating output signals identifying which units of the first group are currently connected by the switching means to units of the second group, storage means having a plurality of storage information locations, and means coupled to the output of the scanning means, the output of the request signal initiating means, the output of each of the locations in the storage means, and the output of the means identifying which units of the first group are connected to units of the second group for inserting the output of the scanning means into a predetermined location in the storage means whenever the scanning means identifies a unit of the first group that is requesting connection to a unit of the second group, the connection has not been initiated by the output of the control means, and the unit identified by the scanner is not identified by the contents of any location in the storage means.

Claim 6

Apparatus for selectively completing electrical connections between any one of a first group of electrical signal generating and/or receiving units and any one of a second group of electrical signal generating and/or receiving units, said apparatus comprising means associated with each of the units of the first group for initiating a request signal identifying the associated unit of the first group seeking connection to a unit of the second group and initiating an address signal identifying a particular unit of the second group to which a connection is being requested, cross-point switching means for selectively completing an electrical connection between any of the first group of units and any of the second group of units, and control means responsive to the request signals and address signals from said request and address signal initiating means for operating the cross points of said switching means to complete electrical connections between the requesting units of the first group and the addressed units of the second group, said control means including scanning means successively identifying each of the units in the first group in time sequence at the output thereof, register means coupled to the output of the control means for generating output signals identifying which units of the first group are currently connected by the switching means to units of the second group, storage means having a plurality of storage information locations, and means coupled to the output of the scanning means, the output of the request signal initiating means, the output of each of the locations in the storage means, and the output of the means identifying which units of the first group are connected to units of the second group for inserting the output of the scanning means into a predetermined location in the storage means whenever the scanning means identifies a unit of the first group that is requesting connection to a unit of the second group, the connection has not been initiated by the output of the control means, and the unit identified by the scanner is not identified by the contents of any location in the storage means.

Claim 7

Apparatus as defined in claim 4 further including gating means for providing signals from the control means to the cross points of the switching means, said gating means being coupled to the output of said register means, the output of the request signal and addressing signal initiating means, the output of the scanning means, and the output from predetermined locations in said storage means for providing an output signal to a selected cross point of the switching means whenever a unit of the first group identified by the contents of either the storage means or the scanner is addressing a unit of the second group which the register means indicates is not connected to a unit of the first group.

Claim 8

Apparatus as defined in claim 5 wherein said means for inserting the output of the scanning means in the storage means includes means indicating the order in which the contents of the storage means were inserted, and priority resolving means for selectively gating signals stored in the several locations in the storage means and the output of the scanner to said gating means on a fixed priority basis, the priority being in the reverse order of said order indicating means with the scanner output having the lowest priority.

Claim 9

Apparatus as defined in claim 6 wherein said order indicating means includes means for transferring the contents of one location in the storage means to another location in predetermined order, and means for operating said transferring means whenever the contents of one of said locations is used to control the switching means.

Claim 10

Apparatus as defined in claim 7 wherein the storage means includes a plurality of stages corresponding in number to one less than the number of requesting units, and said priority resolving means gates only signals stored in all but one of the stages.