[参考译文] TM4C123GH6PM：TM4C123GH6PM 上的串行事件处理

qiang zhang 说：

I 使用的是 USB-CDC 以及 ControlHandler、TxHandler 和 RxHandler。 是否有这样的方式使用常规 UART、我实际上只需要 Rx 处理程序、因此我想可以修改 uart_echo 处的示例以满足我的需求。

您好 CAN、

 我在这里不是很关注你。 下面是 USB-CDC 的 RXHandler。 您希望以这种方式使用常规 UART 是什么意思？ 传递给 RXHandler 的消息事件类型(例如 USB_EVENT_RX_AVAILABLE、USB_EVENT_DATA_RELEASED)特定于 USB CDC 类。 没有要传递给 UART ISR 的参数。 可以使用 UARTSpaceAvail ()来模拟  USB_EVENT_DATA_RELEASED 和 UARTCharGet ()来模拟 USB_EVENT_RX_AVAILABLE。   

uint32_t
RxHandler(void *pvCBData, uint32_t ui32Event, uint32_t ui32MsgValue,
          void *pvMsgData)
{
    uint32_t ui32Count;

    //
    // Which event are we being sent?
    //
    switch(ui32Event)
    {
        //
        // A new packet has been received.
        //
        case USB_EVENT_RX_AVAILABLE:
        {
            //
            // Feed some characters into the UART TX FIFO and enable the
            // interrupt so we are told when there is more space.
            //
            USBUARTPrimeTransmit(USB_UART_BASE);
            MAP_UARTIntEnable(USB_UART_BASE, UART_INT_TX);
            break;
        }

        //
        // We are being asked how much unprocessed data we have still to
        // process. We return 0 if the UART is currently idle or 1 if it is
        // in the process of transmitting something. The actual number of
        // bytes in the UART FIFO is not important here, merely whether or
        // not everything previously sent to us has been transmitted.
        //
        case USB_EVENT_DATA_REMAINING:
        {
            //
            // Get the number of bytes in the buffer and add 1 if some data
            // still has to clear the transmitter.
            //
            ui32Count = MAP_UARTBusy(USB_UART_BASE) ? 1 : 0;
            return(ui32Count);
        }

        //
        // We are being asked to provide a buffer into which the next packet
        // can be read. We do not support this mode of receiving data so let
        // the driver know by returning 0. The CDC driver should not be sending
        // this message but this is included just for illustration and
        // completeness.
        //
        case USB_EVENT_REQUEST_BUFFER:
        {
            return(0);
        }

        //
        // We don't expect to receive any other events.  Ignore any that show
        // up in a release build or hang in a debug build.
        //
        default:
#ifdef DEBUG
            while(1);
#else
            break;
#endif
    }

    return(0);
}

您好 Charles、

我的意思是：USB-CDC 示例以及许多其他数据结构使用中断处理程序、因此在接收到数据包时调用 RxHandler。 非 CDC UART 示例通过在循环中轮询来检测传入的数据来工作。 我错了吗？ 还是在代码 USB-CDC 示例后面使用轮询还是可以？

此致、

CAN