LPC1768 UART3初始化代码

只看该作者 · 2013-3-11 10:23

写了下面的代码初始化UART3，但是死机了，请高手看看是哪里的问题，谢谢！

LPC_PINCON->PINSEL0 &= ~0x0000000A;
LPC_PINCON->PINSEL0 |= 0x0000000A;  /* RxD3 is P0.0 and TxD3 is P0.1 Pin46/47 */
/* By default, the PCLKSELx value is zero, thus, the PCLK for
all the peripherals is 1/4 of the SystemFrequency. */
/* Bit 6~7 is for UART3 */

pclkdiv = (LPC_SC->PCLKSEL1 >> 18) & 0x03;
switch ( pclkdiv )
{
  case 0x00:
  default:
pclk = SystemFrequency/4;
break;
  case 0x01:
pclk = SystemFrequency;
break;
  case 0x02:
pclk = SystemFrequency/2;
break;
  case 0x03:
pclk = SystemFrequency/8;
break;
}

LPC_UART3->LCR = 0x83; /* 8 bits, no Parity, 1 Stop bit */ // 运行这条代码就死机了

Fdiv = ( pclk / 16 ) / baudrate ; /*baud rate */
LPC_UART3->DLM = Fdiv / 256;
LPC_UART3->DLL = Fdiv % 256;
LPC_UART3->LCR = 0x03; /* DLAB = 0 */
LPC_UART3->FCR = 0x07; /* Enable and reset TX and RX FIFO. */

NVIC_EnableIRQ(UART3_IRQn);

LPC_UART3->IER = IER_RBR | IER_THRE | IER_RLS;  /* Enable UART3 interrupt */