Abstract: A system and method for controlling clocking signals including a clock controller that includes a first input operable to receive a first clock signal having a first frequency, a second input operable to receive a second clock having a same frequency as the first clock signal but of arbitrary phase, a first output and a variable delay line coupling the first clock signal received at the first input to the first output. The first output is operable to couple a delayed version of the first clock signal to the receiving device. The clock controller includes a comparator receiving as an input the first and the second clock signals from the first and second inputs and providing as an output to the variable delay line a control signal for adjusting a delay in the first clock signal so as to match a phase of the second clock signal received at the receiving device.

Abstract: A mechanism for routing a communication cell in a cell switching communication controller that employs multiple path identifier masking functions selected by a header control field in the communication cell and that employs a content addressable memory comprising a plurality of entries, wherein each entry stores a pre configured local termination identifier and a pre configured pass through identifier.

Abstract: A method and apparatus for exchanging communication cells in a communication controller, wherein an arbiter determines transmission requests for each of a plurality of communication modules in the communication controller. Each communication module has a transmit signal line and a receive signal line coupled to a switching circuit in the communication controller. The arbiter selectively couples the transmit signal lines to the receive signal lines according to the transmission requests. The communication modules transmit communication cells through the switching circuit, while the arbiter determines new transmission requests from each communication module.

Abstract: A mechanism for buffering communication cells in a communication controller, wherein a cell queuing circuit provides a cell loss priority mechanism, and wherein the cell queuing circuit determines service states for queue channels according to bandwidth allocation parameters. The service states includes a serve.sub.-- now state, a serve.sub.-- ok state, and a no.sub.-- serve state, such that a queue channel is in the serve.sub.-- now state if the queue channel must be serviced to maintain a minimum information rate parameter for the queue channel, the serve.sub.-- ok state if the queue channel can be serviced and not exceed a peak information rate parameter for the queue channel.