[参考译文] CC2652RB：如何清除 UART2的 RxRingBuffer

/*
 * CODE IN INIT
 */
int8_t uart2_init(void)
{
    UART2_Params uartParams2;
    
    /* Create a UART: write in BLOCKING mode, and read in callback mode*/
    UART2_Params_init(&uartParams2);
    uartParams2.baudRate = RSBUS_BAUDRATE;
    uartParams2.readMode = UART2_Mode_CALLBACK;
    uartParams2.readCallback = UART2_read_callback;
    uartParams2.readReturnMode = UART2_ReadReturnMode_PARTIAL;
    
    uartHandle = UART2_open(CONFIG_UART2_RSBUS, &uartParams2);
    if (uartHandle == NULL) {
        /* UART2_open() failed */
        Display_printf(display, 0, 0, "UART2_open failed");
        return FALSE;
    }
}

/*
 * CallBack for uart2 read
 */
void UART2_read_callback(UART2_Handle handle, void *buf, size_t count, void *userArg, int_fast16_t status)
{
    rxBufLen = count;
    sem_post(&get_uart2_cmd);
}

/*
 * Code in main loop
 */
while(1)
{
    static int i = 0, total_len = 0;

    // UART2_flushRx(uartHandle);

    rsbus_send(sendDataBuf, 6);

    do{
        // TODO: the RxRingBuffer must be clear, HOW TO DO?
        UART2_read(uartHandle, rsbusRxBuf, RSBUS_PACK_MAX_LENGTH, NULL);
        sem_wait(&get_uart2_cmd);

        if(rxBufLen > 9 && !memcmp(&rsbusRxBuf[1], addr, 6))
            break;
        else
        {
            int i, len = rxBufLen;
            Display_printf(display, 0, 0, "len(%d <= 9), keep recv", len);
            for(i = 0; i < len; i++)
                Display_printf(display, 0, 0, "0x%02x", rsbusRxBuf[i]);
        }

    } while(1);

    total_len += rxBufLen;
    if(rxBufLen > 9 && rxBufLen < 255)
    {
//      int cnt;
//      Display_printf(display, 0, 0, "recv len: %d, total_len: %d", rxBufLen, total_len);
//      for(cnt = 0; cnt < rxBufLen; cnt++)
//      {
//          Display_printf(display, 0, 0, "%d", rsbusRxBuf[cnt]);
//      }

        Display_printf(display, 0, 0, "HOST recv len: %d, total_len: %d, crc: 0x%02x 0x%02x", rxBufLen, total_len, rsbusRxBuf[rxBufLen-2], rsbusRxBuf[rxBufLen-1]);
    }

    Task_sleep(5000000 / Clock_tickPeriod);
}