CDC-50012: Multiple Clock Domains Driving a Synchronizer Chain

Description

A synchronizer chain is accepting data from multiple clock domains at once. A synchronizer chain can only synchronize data from a single clock domain.

Figure 1. Multi-clock fan-in to synchronizer.

Recommendation

Either synchronize each incoming clock domain with different synchronizer chains in the same destination domain, placing any required combinational logic in the destination domain, or cascade the clock crossings with transfers from one source clock domain at a time.

Figure 2. Proper technique to synchronize multi-clock fan-in to synchronizer.

Severity

High

Tags

Tag Description
synchronizer Design rule checks related to synchronizer chains.

Device Family

  • Intel®Cyclone® 10 GX
  • Intel®Arria® 10
  • Intel®Stratix® 10
  • Intel Agilex®
  • Intel Agilex®