InfiniBand Switch Node Delivers Eight 4X Ports

Crossbar Switch (Hub)
The crossbar is the core switch of the node, connecting all the ports. It functions like a dynamic bus with multiple concurrent connections.

The Arbiter grants the input ports crossbar access. This access can last more than one cycle. It defines a dynamic connection that holds until the packet is rejected or until the packet transfer over the crossbar switch is completed. The crossbar switch supports up to 10 dynamic connections concurrently: one to each of the eight InfiniBand ports, one to the Management port, and one to the Functional BIST port during testing. New requests are queued until one of those 32-bit wide connections frees up.

The crossbar switch handles bad packets by discarding them, or by truncating them, depending on the packet-transfer mode. Incoming packets in the cut-through mode are checked for integrity, and if okay, are passed through the crossbar. Packets with errors are truncated, and a bad packet deliminator and vCRC field are appended to the packet. Packets transferred in the Store-&-Forward mode with errors are truncated.

Management
The HDMP-2840 supports all InfiniBand management agents, either directly in hardware, or indirectly via an external management processor. The Management block processes all InfiniBand management packets, including the Subnet Management, Performance Management, and Baseboard Management packets. As an option, these packets can be transferred to the external processor for off-chip processing.

The Management block management tasks include:

• Initialization—initializes the switch node, including setting up the routing tables and VLs.
• Decoding—decodes and dispatches packets to their owners.
• Grant Control—handles both unsolicited and solicited Grant signals from the switch Arbiter.
• Request Control—submits requests to the Arbiter for Management Port packets for packet routing.
• Flow Control Buffer—manages credits for the VL (VL0) packets.
• Management Port IAL—manages the Internal Access Loop for chip test.

Price & Availability
The HDMP-2840 samples in November, with production in the second quarter of 2002. It costs $600 in 1000-unit lots.

Red Switch, 1815 McCandless Dr., Milpitas, CA 95035; (408) 719-4888; fax (408) 719-4800; www.redswitch.com.