GigaDevice Semiconductor GD32 Series, User Manual

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AN050
GD32 USBFS&USBHS Firmware Library User Guide
47
fail.
5.7.6.
USB printer
Printer descriptor introduction
Device descriptor include Printer device VID(0x28e9) and PID(0x028d). In printer
configuration descriptor set, include configuration, interface and endpoint descriptor,
corresponding descriptor is shown as below.
Printer device class interface
Printer device class interface is shown in below structure, and structure function is shown in
below
Table 5-23. printer device class interface function .
usb_class_core usbd_printer_cb = {
. init = printer_init ,
. deinit = printer_deinit ,
. req_proc = printer_req ,
. data_in = printer_in ,
. data_out = printer_out
};
Table 5-23
. printer device class interface function
Function name Functional description
printer_init Initialize printer device
printer_deinit Deinitialize printer device
printer_req Printer device class request function
printer_in IN data transfer callback
printer_out OUT data transfer callback
Printer device class request
Priner device include device class request is shown in Table 5-24. printer device class
request .
Table 5-24
. printer device class request
Request name value Functional description
GET_DEVICE_ID 0x00 Get device ID
GET_PORT_STATUS 0x01 Get port status
SOFT_RESET 0x02 Software reset
Printer user interface
Currently, printer rountine merely implement enumeration, data transfer is subject to printer
hardware, and without corresponding user interface, which is used to implement data transfer