Signal phase verification for systems incorporating two synchronous clock domains

Abstract

The present invention implements a mechanism which enables zero-delay verification tools to detect clock domain crossing violations in device under test designs comprising two different clock domains where the fast clock rate is an integer multiple of the slow clock rate by inserting undefined (i.e., invalid) values on slow clock domain signals during the clock periods when the signals are not supposed to be captured. The undefined values are contained in the logic cone and emulate timing uncertainty of the path. Propagation of the undefined values through the capturing latch indicates improper clock domains crossing handling.