USB power supply Circuit analysis

PA6, PA7 usb_id usb_on all pull high
USB_ID: High voltage trigger external USB for charging
USB_ON: Used to test the sub has been powered, plug the USB

Internal Charging Mode Analysis:
The handle is plugged into an external power supply and the vbus level is high.
At this point the usb_id level is high, open the Q11 Morse tube, enter the power chip pin 1,24vbus.
The external power supply is charged to the handle.

External Charging Mode analysis:
When usb_id is low, the CPU detects a function that enters the following:
Boost_enable ();
Rvs_enable ();
Enter boost mode, rvs_en pull high
Then enter the charging mode.