There are 3 types usb driver in wince system. They areusb host driver, usb slave driver, usb otg driver.
1, usb host driver
Whendevice was plug in, system enume the register according the device descriptorand interface descriptor, then load the usb client driver, call theusbdeviceattach function. Normaly, usb client driver will support stream driverinterface, in usbdeviceattach function, the stream driver will be actived
2,usbslave driver
Usbfn.dllwill be loaded by system devicemanager at system startup steps. Then if thedevice was plug in host hub, usbfn.dll will detect power changed, then try toload usb client driver according to register key. Here the client driver can berndisfn, uartfn, storagefn.
转载于:https://blog.51cto.com/bluefish/1239085