Metod och arrangemang för att förhindra metastabilitet

摘要

A system and method of preventing metastability in conjunction with the receipt in a first clock domain of an asynchronous digital signal from a second clock domain when the first domain operates with a first clock frequency, and the second domain operates with a second clock frequency that is known within the first domain. The first domain sends information to the second domain, and includes a reference signal containing phase information known in the first domain. The information is clocked into the second domain utilizing the reference information. The second domain then sends the asynchronous digital signal to the first clock domain. A receiving unit in the first domain determines the phase information from the received signal with a known degree of maximum uncertainty that is less than one period of the reference signal. The first domain then stably reads the received asynchronous digital signal.