Switchcore, A.b.

Jonas Alowersson

Bertil Roslund

Per Andersson

Patrik Sundstr&ouml;m

Patrik Sundström

Converters and a corresponding method for converting serial data to parallel format and vice versa, particularly for use in switches for telecommunications applications. The converters comprise a storage element associated with each serial channel and comprising two arrays of storage elements. At any one time, the storage elements are accessed sequentially while those of the other array are accessed in parallel. A data bus, divided into portions by buffers, connects the by buffers, connects the serial channel to all storage cells in an associated storage element. For serial to parallel conversion, the buffers latch data from one bus portion to the next in accordance with a write cycle during which one storage element is written. Writing commences from the bus portion furthest from the incoming serial channel and storage elements on either side of a buffer are written simultaneously. The resulting delay between writing arrays words allows checking of the data such as synchronization.

Apparatus and method for converting data in serial format to parallel format and vice versa

The invention relates to a buffer memory, method and a buffer controller for queue management usable in an ATM switch. An object of the invention is to achieve a high frequency throughput of data cells in the buffer memory. This object is achieved by using a buffer memory which is organized as 256*(424&plus;8) SRAM-cells. The memory is used for holding ten queues, one for each incoming channel and two free-queues containing idle cells.

Queue management system having one read and one write per cycle by using free queues

The invention relates to a method and an arrangement for multicasting, i.e. point to multipoint transmission of a data packet. A packet is copied and transmitted to multiple addresses. In the multicasting arrangement, switch core and input and output port are connected to input and output links, respectively, for transmitting data packets. According to the invention, the input port is adapted to detect a multicasting packet received on an input link or from an output port and send the multicasting packet to an output port. The output port is adapted to detect the multicasting packet, copy the data packet, modify an address portion of the multicasting packet, send one packet on the output link and return one packet with the modified address portion to an input port. Preferably, the input port and the output port are integrated in a link interface having a direct channel for returning the data packet. The present invention improves the efficiency of multicasting by distributing copying of the data packets on several output ports of the switch core (e.g. an ATM switch).

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Malmö, Sweden

Jonas Alowersson