A clock crossing FIFO capable of functioning regardless of relative clock frequencies on the write and read sides. Toggle signals are utilized to cross the clock boundaries. The number of write counts which have been accrued but not acknowledged by the read side are tracked, and this number is stored...http://www.google.co.uk/patents/US6098139?utm_source=gb-gplus-sharePatent US6098139 - Frequency independent asynchronous clock crossing FIFO
