A new FIFO design enabling fully-synchronous on-chip data communication network

Abstract

A new FIFO design that enables fully synchronous circuits with unrelated clocks to communicate synchronously is proposed. Not only would every circuit be running on its own clock, but the interconnection network is fully synchronous and runs at an unrelated clock of its own. With relatively low gate count, the proposed FIFO allows communicating circuits to put/get data at their respective frequencies (1 datum/clock cycle) till it gets filled then the rates converge to the lower frequency. The maximum initial latency is 3 cycles of the consumer's clock. Several manifestations of the proposed FIFO have been developed for different design cases including data width mismatch between producer and consumer. The operation of different FIFOs has been verified using gate-level simulations for several ratios of clock frequencies. An 8-cell FIFO has been designed at the transistor-level and Spice simulations using a 0.13 μm, 1.2V technology has been carried out. It shows proper operation at producer and consumer clock frequencies of 2GHz and 3.125GHz, respectively, with a data transfer rate of more than 2Giga datum/second and an average power of 721 μW.