Abstract: A method and an apparatus for reducing power consumption and digital logic noise in a time division multiplexed memory switch. The method is embodied in an egress selection switch (ESS) block architecture. The ESS block includes a data disable block which prevents the propagation of data, in particular ingress grains, to a given group of egress ports if the data is not selected by any of the egress ports in a given group. While the ingress data disable method partitions ports into groups and saves power by disabling the fanout tree from the root on a port group basis, the egress data disable method saves power on a port group basis by disabling the fanout tree from the tail end in addition to applying the ingress data disable method. The ESS block also includes an grain select block for selecting and storing a given ingress grain for eventual output to an egress port.

Abstract: A method of time division multiplex switching reduces the implementation area by reducing the area required for both memory storage at each egress port and the multiplexing circuitry required. Ingress and egress processors are implemented to control the storage and selection of data grains to allow for the reduction in the memory and multiplexer areas.

Abstract: A method and an apparatus for reducing power consumption and digital logic noise in a time division multiplexed memory switch. The method is embodied in an egress selection switch (ESS) block architecture. The ESS block includes a data disable block which prevents the propagation of data, in particular ingress grains, to a given group of egress ports if the data is not selected by any of the egress ports in a given group. While the ingress data disable method partitions ports into groups and saves power by disabling the fanout tree from the root on a port group basis, the egress data disable method saves power on a port group basis by disabling the fanout tree from the tail end in addition to applying the ingress data disable method. The ESS block also includes an grain select block for selecting and storing a given ingress grain for eventual output to an egress port.

Abstract: A method and system are provided for opportunistic request-grant switching. If an ingress has no granted payload segment to send, and a flow exists which requires a request to be sent, an opportunistic payload segment is sent including a request and a payload segment related to the request. If an opportunistic payload segment is sent and the payload is dropped, the request is kept and is then treated as a regular request-grant request. The ingress port consequently only has to transmit the payload a maximum of twice. Ingress ports can thus opportunistically exploit the low latency available when egress ports are not contended for, and yet fall back on the strong fairness and quality of service (QoS) assurances of request-grant semantics. Buffering in the switch core can optionally be implemented to extend performance gains, but fairness and QoS are not dependent on this buffering.

Abstract: A method of adding a new connection (c, d) to a time:space:time switch fabric. The fabric has a set I of k input elements, a set M of m switch elements, and a set O of l output elements. Each input element contributes one input to each switch element, and each output element receives one output from each switch element. A state Sm characterizes the switch elements as a set of ordered pairs (i, j), where (i, j) ? Sm if and only if the jth output element is coupled to the ith input element through one of the switch elements. The range of Sm is the set of outputs of Sm such that if j ? range(Sm) then (i, j) ? Sm for some i ? I. The domain of Sm is the set of inputs of Sm such that if i ? domain(Sm) then (i, j) ? Sm for some j ? O.

Abstract: A time:space:time switch fabric incorporating an odd integer number of spatially distributed data switches and a plurality of spatially distributed data serializers. Each data switch has a first plurality of ingress ports, an equal plurality of egress ports, and a space switch for selectably interconnecting any one of the ingress ports to any one of the egress ports. Each data serializer has an input bus for receiving signals to be routed through the switch fabric, an output bus for outputting signals routed through the switch fabric, a plurality of egress ports selectably connectible to any one of the data switch ingress ports, and an equal plurality of ingress ports selectably connectible to any one of the data switch egress ports.

Abstract: A time:space:time switch fabric incorporating an odd integer number of spatially distributed data switches and a plurality of spatially distributed data serializers. Each data switch has a first plurality of ingress ports, an equal plurality of egress ports, and a space switch for selectably interconnecting any one of the ingress ports to any one of the egress ports. Each data serializer has an input bus for receiving signals to be routed through the switch fabric, an output bus for outputting signals routed through the switch fabric, a plurality of egress ports selectably connectible to any one of the data switch ingress ports, and an equal plurality of ingress ports selectably connectible to any one of the data switch egress ports.

Abstract: A method of adding a new connection (c, d) to a time:space:time switch fabric. The fabric has a set I of k input elements, a set M of m switch elements, and a set O of l output elements. Each input element contributes one input to each switch element, and each output element receives one output from each switch element. A state Sm characterizes the switch elements as a set of ordered pairs (i, j), where (i, j) &egr; Sm if and only if the jth output element is coupled to the ith input element through one of the switch elements. The range of Sm is the set of outputs of Sm such that if j &egr; range(Sm) then (i, j) &egr; Sm for some i &egr;I. The domain of Sm is the set of inputs of Sm such that if i &egr; domain(Sm) then (i, j) &egr; Sm for some j &egr; O. If a switch state Sm exists where c ∉ domain(Sm) and d ∉ range(Sm), then the new connection is added to Sm as (c, d).