LPC1788: uart mit 921600 baud

uint32_t UARTInit( uint32_t baudrate )

{

  uint32_t Fdiv;

  uint32_t pclkdiv, pclk;

  LPC_PINCON->PINSEL0 &= ~0x000000F0;

  LPC_PINCON->PINSEL0 |= 0x00000050;  /* RxD0 is P0.3 and TxD0 is P0.2 */

  /* 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 UART0 */

  pclkdiv = (LPC_SC->PCLKSEL0 >> 6) & 0x03;

  LPC_SC->PCLKSEL0 |= (0x01 << 6);

  pclkdiv = (LPC_SC->PCLKSEL0 >> 6) & 0x03;

  switch ( pclkdiv )

  {

  case 0x00:

  default:

    pclk = SystemCoreClock/4;

    break;

  case 0x01:

    pclk = SystemCoreClock;

    break;

  case 0x02:

    pclk = SystemCoreClock/2;

    break;

  case 0x03:

    pclk = SystemCoreClock/8;

    break;

  }

  LPC_UART0->LCR = 0x83;    /* 8 bits, no Parity, 1 Stop bit */

  Fdiv = ( pclk / 16 ) / baudrate ;  /*baud rate */

  LPC_UART0->DLM = Fdiv / 256;

  LPC_UART0->DLL = Fdiv % 256;

  LPC_UART0->LCR = 0x03;    /* DLAB = 0 */

  LPC_UART0->FCR = 0x07;    /* Enable and reset TX and RX FIFO. */

  NVIC_EnableIRQ(UART0_IRQn);

  LPC_UART0->IER = IER_RBR | IER_THRE | IER_RLS;  /* Enable UART0 interrupt */

  return (1);

}