CDC-50102: Synchronizer after CDC Topology with Control Signal

Description

Violations of this rule identify a synchronizer chain that follows a CDC topology managed by a control signal, such as a clock enable or MUX select signal. Such transfers may not require being followed by a synchronizer, as they are already synchronized by the control signal.

Figure 1. A CE-type synchronizer followed by a deduced synchronizer chain.

Recommendation

For any control-signal-managed CDC topology that does not need to be followed by a synchronizer, apply an instance assignment of Synchronization Register Chain Length = 1 on the destination of the CDC.

Severity

Low

Tags

Tag Description
synchronizer Design rule checks related to synchronizer chains.
false-positive-synchronizer Design rule checks related to automatically-deteected synchronizer chains that may have been over-zealously detected.

Device Family

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