Raghu Sastry

A 285 MHz 6-port plesiochronous router chip with non-blocking cross-bar switch

The HAL router chip is a 285 MHz 6-port plesiochronous packet-switched routing chip with non-blocking cross-bar switch. It combines very high bandwidth (4.5 GByte/s per port, 27 GByte/s total raw bandwidth), low fall-through latency (32 ns), no internal blocking, three arbitration priorities with in-order delivery, a flexible source routing scheme, virtual-cut-through routing, and robust reverse flow control.

A 9.6 GigaByte/s throughput plesiochronous routing chip

The design of a very high performance routing chip with six bi-directional link ports and an aggregate sustained throughput of 9.6 GByte/s is described The routing chips will form the switching fabric of a cache-coherent, Non-Uniform Memory Access (cc-NUMA) multiprocessor system. The key elements of the chip are a non-blocking internal crossbar; synchronization circuits for plesiochronous operation (i.e. no central system clock required) and reliance on hardware end-to-end error checking. The chip has recently been taped out.