Eleven Ways to Boost Your Synchronizer

Synchronizers play an essential role in multiple clock domain systems-on-chip. The most common synchronizer consists of a series of pipelined flip-flops. Several factors influence the performance of synchronizers: circuit design, process technology, and operating conditions. Global factors apply to the entire integrated circuit, while others can be adjusted for each individual synchronizer in the design. The following guidelines are provided to improve synchronizers: avoiding scan and reset, selecting minimum size flip-flop cells, minimizing routing, reducing jitter in coherent clock domain crossings, opting for high-performance process flavor and minimumV_TH, overprovisioning to account for variations, maximizing supply voltage, and manipulating clock duty cycle.