Patent ID: 8289989
Filing Date: 2012-10-16
Classification: H04L

Abstract:
1. A method for arbitration in a packet switch comprising a first plurality of input ports a first plurality of output ports, an arbitrator and a plurality of grant request filters, each of the plurality of grant request filters associated with one of each of the plurality of input ports, the method comprising: receiving a data packet at a first input port of the first plurality of input ports of the packet switch; issuing a grant request from the first input port to a first grant filter associated with the first input port in a first clock cycle, the grant request issued in response to the data packet received at the first input port, the grant request identifying a first pseudo-port of a plurality of pseudo-ports; generating an availability signal at an arbiter in a first clock cycle, the arbiter generating the availability signal without receiving the grant request from the first input port identifying the first pseudo-port of the plurality of pseudo-ports, the availability signal including an availability indicator for each pseudo-port of the plurality of pseudo-ports, wherein each pseudo-port identifies a second plurality of output ports in the first plurality of output ports of the packet switch, each availability indicator for each pseudo-port indicating whether or not the pseudo-port will be available to receive data from any input port of the first plurality of input ports in a second clock cycle, wherein the second clock cycle follows the first clock cycle; receiving the grant request issued from the first input port and the availability signal at the first grant request filter associated with the first input port; determining whether or not the grant request received at the first grant request filter is a serviceable grant request, wherein the grant request is identified as being a serviceable grant request if the first pseudo-port identified by the grant request will be available to receive data in the second clock cycle, and wherein the first pseudo-port is available to receive data in the second clock cycle if the availability signal indicates that each output port of the second plurality of output ports of the packet switch is available to receive data in the second clock cycle; and issuing the grant request from the first grant request filter to the arbiter only if the grant request is determined to be a serviceable grant request.