Alcatel Canada Inc.

Albert D Heller

Mark William Janoska

Henry Chow

Hossain Pezeshki-Esfahani

Jason Chung-Shih Chen

Paul M Ruffle

A method and apparatus is for buffering data cells in a queuing element is presented. Each queuing element includes a partitioned buffer, where the partitioned buffer includes a plurality of partitions. Each of the partitions stores data cells received by the queuing element. Storage of the data cells into the partitions is accomplished by using an array of logical queues. Each logical queue of the array of logical queues maps data cells corresponding to that logical queue to a particular partition of the plurality of partitions. More than one logical queue may map data cells to a particular partition. Each partition may include a reserved portion, where each logical queue that maps to the partition may map a portion of its data cells to the reserved portion. The resources of the reserved portion to which a logical queue maps data cells are reserved to that specific logical queue and cannot be utilized by other logical queues. Each partition also includes a shared portion, where all of the logical queues that map to a partition are able to utilize the storage space included in the shared portion. Each logical queue includes a maximum size. Depth pointers corresponding to the logical queue and the partition are updated as data cells are enqueued to, and dequeued from, the logical queue.

Method and apparatus for data buffer management in a communications switch

A method and apparatus for a high bandwidth multi-source interconnection using point-to-point buses that may be utilized in a communication switch is presented. In the communication switch, a number of output buffers are included to correspond to the outputs of the switch. Each output receives data from a number of different inputs to the switch. Each output buffer includes a plurality of queuing elements where each queuing element receives data from at least one of the inputs and buffers the data prior to insertion into an output data stream corresponding to the output of the output buffer. The plurality of queuing of elements are intercoupled in a daisy chain configuration such that a daisy chain output of one queuing element is coupled to the daisy chain input of the succeeding queuing element. The daisy chain configuration provides a data path through which a data stream that becomes the output of the output buffer is carried. A chain master queuing element at the head of the daisy chain inserts idles into the data stream unless an arbiter has instructed it to insert data that it has received from its corresponding inputs. Succeeding queuing elements on the daisy chain then receive the data stream and insert their data at the appropriate time determined by the arbitration grants received from the arbiter.

Method and apparatus for high bandwidth multi-source interconnection using point-to-point buses

A method and apparatus for load distribution across memory banks with constrained access is accomplished using a bank balancer that ensures that data to be buffered is evenly distributed throughout the various banks of the memory structure. The bank balancer maintains bank depth information relating to each of the banks. The bank balancer receives dequeue and enqueue information, where the dequeue information specifies read operations that will remove data from the various banks, and the enqueue information indicates that there is data to be written to the memory banks. The dequeue information constrains which banks may be utilized to enqueue received data. In order to determine to which banks to enqueue data, the bank balancer sorts the banks by their depth. The bank balancer then eliminates those banks which cannot be used for enqueue operations due to either the dequeue operations or other enqueue operations that have already been determined. Once a sorted list of eligible banks for enqueuing has been established, the bank balancer selects the bank storing the least amount of data which is eligible. The depth information for each bank is updated based on the enqueue and dequeue operations, and the bank balancer re-sorts the banks such that the changes in depth are taken into account in the following cell period.

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Kanata, Canada

Albert D Heller