STM32F4 USB OTG寄存器CID
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 pingin 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;
[*] }
[*]
[*]}
复制代码
手册有介绍的,重点看看OTG_HS_GOTGCTL和 OTG_HS_GINTSTS两个寄存器
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