Low-latency asynchronous FIFO buffers

A parallel asynchronous implementation of a FIFO buffer is described and compared with the conventional alternative asynchronous implementation, Sutherland's micropipeline. The parallel design has the potential for significant reductions in propagation delay at the cost of insignificant increases in cycle-time (i.e. reduced throughput) and area. Although in certain applications, e.g. DSP, only high throughput may be important, in others, e.g. packet switching, throughout and propagation delay both matter. We consider the parallel design to be most useful as part of the interface circuitry required by devices that asynchronously exchange data in bursts over inter-chip communication wires and use a single acknowledge signal for each burst of data. In particular, a high-throughput multiple-burst signalling scheme is supported, in which a second burst of data is transmitted at the same time as the previous burst is acknowledged, effectively increasing the overall throughput