Patent ID: 9529756
Filing Date: 2016-12-27
CPC Classification: G06F

Claim Text:
1. A method for starting a Universal Serial Bus (USB) state machine, comprising: fixing a USB voltage bus pin to a certain logic level; when detecting that a voltage of a charging voltage pin is greater than a threshold limit value, starting both a charging state machine and a USB state machine; wherein, after the step of starting both the charging state machine and the USB state machine, the method further comprises: when detecting that the voltage of the charging voltage pin is less than or equal to said threshold limit value, quitting both the charging state machine and the USB state machine; thereby both the charging state machine and the USB state machine are started and quit through the voltage of the charging voltage pin for detecting plug-in and pull-out of a charger; wherein, the logic level is a high level and the high level is not greater than a withstand voltage value of the USB voltage bus pin, and the method further comprises: before monitoring the voltage of the charging voltage pin, shielding a USB session interruption; or wherein, the step of fixing the USB voltage bus pin to a logic level comprises: grounding the USB voltage bus pin, and the logic level of the USB voltage bus pin is fixed and will never be changed.