Some implementations disclosed herein provide techniques and arrangements for transferring data between asynchronous clock domains. A synchronization signal may be generated by a first of the clock domains, and data may be transferred between the domains in response to the synchronization signal. Clock cycles of the second of the clock domains may be monitored in comparison to the synchronization signal to report the number of second clock domain cycles occurring per occurrence of the synchronization signal. This information may be recorded by testing and validation equipment to facilitate error analyses.