STM32F4 USB OTG寄存器CID

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huahuahnu 提问时间：2022-10-17 11:01 / 未解决

问答
是否解决:	未解决

USB库函数里有些地方判断CID寄存器的bit8位，1或0执行不同操作，请问这位代表什么意思？参考手册上没有介绍

1、
if ((USBx->CID & (0x1U << 8)) != 0U)
{
if (cfg.speed == USBH_FSLS_SPEED)
{
/* Force Device Enumeration to FS/LS mode only */
USBx_HOST->HCFG |= USB_OTG_HCFG_FSLSS;
}
else
{
/* Set default Max speed support */
USBx_HOST->HCFG &= ~(USB_OTG_HCFG_FSLSS);
}
}
else
{
/* Set default Max speed support */
USBx_HOST->HCFG &= ~(USB_OTG_HCFG_FSLSS);
}
2、
if ((USBx->CID & (0x1U << 8)) != 0U)
{
/* set Rx FIFO size */
USBx->GRXFSIZ = 0x200U;
USBx->DIEPTXF0_HNPTXFSIZ = (uint32_t)(((0x100U << 16) & USB_OTG_NPTXFD) | 0x200U);
USBx->HPTXFSIZ = (uint32_t)(((0xE0U << 16) & USB_OTG_HPTXFSIZ_PTXFD) | 0x300U);
}
else
{
/* set Rx FIFO size */
USBx->GRXFSIZ = 0x80U;
USBx->DIEPTXF0_HNPTXFSIZ = (uint32_t)(((0x60U << 16) & USB_OTG_NPTXFD) | 0x80U);
USBx->HPTXFSIZ = (uint32_t)(((0x40U << 16)& USB_OTG_HPTXFSIZ_PTXFD) | 0xE0U);
}
3、
if ((USBx->CID & (0x1U << 8)) != 0U)
{
USBx_HC((uint32_t)ch_num)->HCINTMSK |= USB_OTG_HCINTMSK_NYET |
USB_OTG_HCINTMSK_ACKM;
}
4、
if (((USBx->CID & (0x1U << 8)) != 0U) && (hc->speed == USBH_HS_SPEED))//CID bit8 host
{
/* in DMA mode host Core automatically issues ping in case of NYET/NAK */
if ((dma == 1U) && ((hc->ep_type == EP_TYPE_CTRL) || (hc->ep_type == EP_TYPE_BULK)))
{
USBx_HC((uint32_t)ch_num)->HCINTMSK &= ~(USB_OTG_HCINTMSK_NYET |
USB_OTG_HCINTMSK_ACKM |
USB_OTG_HCINTMSK_NAKM);
}
if ((dma == 0U) && (hc->do_ping == 1U))
{
(void)USB_DoPing(USBx, hc->ch_num);
return HAL_OK;
}
}