GigaDevice Semiconductor GD32 Series, User Manual

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AN050
GD32 USBFS&USBHS Firmware Library User Guide
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Descriptor name Functional description
usb_desc_input_terminal input terminal descriptor
usb_desc_mono_feature_unit mono feature unit descriptor
usb_desc_output_terminal output terminal descriptor
usb_desc_AS_itf AS interface descriptor
usb_desc_format_type format type descriptor
usb_desc_std_ep standard endpoint descriptor
usb_desc_AS_ep AS endpoint descriptor
AUDIO device class interface
AUDIO device class interface is shown as below struct, the function of struct is referred to
Table 5-5. AUDIO device class interface function .
usb_class_core usbd_audio_cb = {
. init = audio_init ,
. deinit = audio_deinit ,
. req_proc = audio_req_handler ,
. ctlx_out = audio_ctlx_out ,
. data_in = audio_data_in ,
. data_out = audio_data_out ,
. SOF = usbd_audio_sof
};
Table 5-5
. AUDIO device class interface function
Descriptor name Functional description
audio_init Initialize AUDIO device
audio_deinit deinitialize AUDIO device
audio_req_handler AUDIO device class request function
audio_ctlx_out OUT control transfer callback
audio_data_in IN data transfer callback
audio_data_out OUT data transfer callback
usbd_audio_sof SOF event callback
AUDIO device class request
AUDIO contains individual device class requests as shown Table 5-6. AUDIO device class
request .
Table 5-6
. AUDIO device class request
Request name Functional description
AUDIO_REQ_SET_CUR set current value request
AUDIO_REQ_GET_CUR get current value request
AUDIO_REQ_SET_MIN set minimum value request
AUDIO_REQ_GET_MIN get minimum value request