A self routing crossbar switch for multiple channel delta networks

The architecture and operation of a self-routing crossbar switch with multiple channels per input and output port are described. The crossbar is the building block for an asynchronous transfer mode switch fabric using delta networks with multiple links and shared output buffers. Each crossbar switch concurrently processes bit-serial packets, using the packet headers for path setup and arbitration. The architecture consists of a pipeline of sorting and routing cells which permits high speed routing of the packets. A prototype 4×4 crossbar with two channels per port has been designed in 2-μm double-metal single-poly CMOS and simulations indicated an operating speed of 50 MHz. The design and implementation of the sorting and routing cells and the switch architecture that accommodates them are described in detail