Abnormality detection and recovery circuit means and method Usb

The present invention provides an abnormality detection and recovery circuit and method of the USB device, comprising: a phase lock loop unit, a data transceiver unit, and the labeled marker data detection unit watchdog unit. Wherein the phase lock loop means for generating a clock signal. A data transceiver unit is coupled to phase lock loop means for receiving the channel signal and the sampling clock signal according to the channel data bus signal is generated. Mark data detecting unit is coupled to a data transceiver unit for detecting the marking data on the data bus generates a control signal. The watchdog unit is coupled to mark flag data detecting means, when the control signal for the tag data indicates the detection unit does not detect the tag and data after a predetermined time, generates a reset signal to the phase lock loop unit, data transceiving unit and a micro control unit.