Functional verification of clock domain crossing (CDC) signals is normally concluded on a register-transfer level (RTL) representation of the design. However, physical design implementation during the back-end pre-silicon stages of the flow, which turns the RTL into an optimized gate-level representation, can interfere with synchronizer operation or compromise the effectiveness of the synchronizers by eroding the mean time between failures (MTBF). This paper aims to enhance cross-discipline awareness by providing a comprehensive explanation of the problems that can arise in the physical implementation stages including a detailed analysis of timing intent for common synchronizer circuits.

( Mark Litterick )