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Comet NP |
The Comet NP has unique packet processing engine named Stream Processors and two 64bit/66MHz PCI interfaces. Each SP recognizes the input packet data word as an instruction and perform processing to it. The SP has some functional blocks like a table lookup engine and a DES/3DES engine. Using 0.35um low-cost CMOS technology, each SP achieves over 250Mbps IPsec ESP with 3DES at 80MHz.
The Comet NP has two SPs and two PCI interfaces connected via FIFOs. One PCI interface has a Message Queue Facility which realizes virtual interfaces (VIs) of the Comet VIA. Usually the PCI interface is used for a host interface and the other PCI is used for network interfaces.
The Stream Processor performs data processing while the DMA is running. This architecture reduces processing delay compared with conventional store and forward processing using a memory and a CPU.
When a data word arrived at the input FIFO, the Stream Processor recognizes the word as an instruction and an appropriate horizontal microcode is selected. The microcode controls functional blocks and sends the data word to the selected functional blocks. Parallel processing by these functional blocks are easily performed. The processed output is sent to the output FIFO.
