A method of reacquiring clock synchronization on a non-tracking helical scan tape device

摘要

A method and apparatus for reacquiring synchronization of a clock synchronization signal with a data signal in a non-tracking storage device is presented. A packet error detector detects errors in data packets from a data signal and generates a packet error status for each reconstructed packet. A read quality detector monitors the packet error status and determines whether the quality of the data signal is of an acceptable versus unacceptable read quality condition. The read quality condition is based on the number of consecutive packets in which an error is detected. Upon detection of an unacceptable read quality condition, the read channel is disabled and the clock synchronize signal is relocked to a known reference frequency. The read channel is then reenabled and the clock synchronization signal is relocked to the data signal.