Multi-clock domain circuits with Clock Domain Crossing (CDC) interfaces are emerging as an alternative to circuits with a global clock. CDC interfaces are susceptible to metastability, hence their design is very challenging. This paper presents a hybrid FIFO-asynchronous method for constructing robust CDC interfaces. The proposed design can handle arbitrary clock frequency ratios between the sender and receiver with random phase shifts. The proposed design avoids latency due to synchronizers with the asynchronous protocol modifications. Circuit simulation results confirm the operation and robustness of the design at maximum workloads, and arbitrary frequency ratios, over a temperature range of -50 to 50 degrees Celsius. The interface offers a maximum throughput of 606 million transfers per second without pausing the clock.
['Zaid Al-bayati', 'Otmane Ait Mohamed', 'Syed Rafay Hasan', 'Yvon Savaria']
A novel hybrid FIFO asynchronous clock domain crossing interfacing method