GigaDevice Semiconductor GD32 Series, User Manual

Page: 24 / 65

AN050
GD32 USBFS&USBHS Firmware Library User Guide
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return 1U ;
}
In OUT endpoint interrupt handler function, depending on the interrupt flag register,
out_endp_intr function judge the event of OUT endpoint interrupt, which include transfer
finished interrupt and setup phase finished interrupt. After corresponding OUT endpoint
interrupt event generated, MCU execute the corresponding interrupt handler function through
polling interrupt flag.
The interrupt handler function of IN endpoint is shown as below:
static uint32_t usbd_int_epin ( usb_core_driver * udev )
{
uint32_t epintnum = 0U ;
uint8_t ep_num = 0U ;
for ( epintnum = usb_iepintnum_read ( udev ); epintnum ; epintnum >>= 1 , ep_num ++) {
if ( epintnum & 0x1U ) {
__IO uint32_t iepintr = usb_iepintr_read ( udev , ep_num );
if ( iepintr & DIEPINTF_TF ) {
udev -> regs . er_in [ ep_num ]-> DIEPINTF = DIEPINTF_TF ;
/* data transmission is completed */
( void ) usbd_in_transc ( udev , ep_num ); // IN transaction
if (( uint8_t ) USB_USE_DMA == udev -> bp . transfer_mode ) {
if (( 0U == ep_num ) && (( uint8_t ) USB_CTL_STATUS_IN ==
udev -> dev . control . ctl_state )) {
usb_ctlep_startout ( udev );
}
}
}
if ( iepintr & DIEPINTF_TXFE ) {
usbd_emptytxfifo_write ( udev , ( uint32_t ) ep_num ); // write FIFO
udev -> regs . er_in [ ep_num ]-> DIEPINTF = DIEPINTF_TXFE ;
}
}
}
return 1U ;
}