Kenneth Donald Norton

US Patent:

58986880, Apr 27, 1999

Filed:

May 24, 1996

Appl. No.:

8/653259

Inventors:

Kenneth Norton - Santa Barbara CA
Mark Rumer - Santa Barbara CA

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

H04L 1256

US Classification:

370362

Abstract:

A network switch includes a plurality of cell processing units coupled together via a switch bus. In a preferred embodiment, the switch bus supports the peripheral component interconnect (PCI) bus protocol. Each cell processing unit includes a segmentation and reassembly unit (SAR), a RISC processor, a port processor, and a bus control unit. The SAR generates cells from frames of data stored in memory and transfers those cells to a destination mailbox in response to commands from from the RISC processor. The SAR assembles a cell within an internal register by combining cell header information with payload data read from memory. Once a cell has been assembled, it is sent to the bus controller for transmission across the switch bus to an address given by a mailbox number. Cells are transferred across the switch bus using a PCI burst write to the mailbox. A reassembly function gathers 48-byte cells into one or more larger output buffers.