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how to set LPC_UART1->LCR value

i am using lpc 1768 but i dont know how to set how to set LPC_UART1->LCR=?? value for 4800 baud,8 data bits,odd parity,1 stop.I hope that someone help me. Thank you.

Parents

0 John Linq over 11 years ago in reply to dhanaraj shanmugam

\mcb1700.code_.bundle.lpc17xx.keil_\keil_examples\UART

/****************************************************************************
 *   $Id:: uart.c 5751 2010-11-30 23:56:11Z usb00423                        $
 *   Project: NXP LPC17xx UART example
 *
 *   Description:
 *     This file contains UART code example which include UART initialization,
 *     UART interrupt handler, and APIs for UART access.
 *
 ****************************************************************************
 * Software that is described herein is for illustrative purposes only
 * which provides customers with programming information regarding the
 * products. This software is supplied "AS IS" without any warranties.
 * NXP Semiconductors assumes no responsibility or liability for the
 * use of the software, conveys no license or title under any patent,
 * copyright, or mask work right to the product. NXP Semiconductors
 * reserves the right to make changes in the software without
 * notification. NXP Semiconductors also make no representation or
 * warranty that such application will be suitable for the specified
 * use without further testing or modification.
****************************************************************************/

/*****************************************************************************
** Function name:               UARTInit
**
** Descriptions:                Initialize UART port, setup pin select,
**                                              clock, parity, stop bits, FIFO, etc.
**
** parameters:                  portNum(0 or 1) and UART baudrate
** Returned value:              true or false, return false only if the
**                                              interrupt handler can't be installed to the
**                                              VIC table
**
*****************************************************************************/
uint32_t UARTInit( uint32_t PortNum, uint32_t baudrate )
{
  uint32_t Fdiv;
  uint32_t pclkdiv, pclk;

  if ( PortNum == 0 )
  {
        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;
        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_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 (TRUE);
  }
  else if ( PortNum == 1 )
  {
        LPC_PINCON->PINSEL4 &= ~0x0000000F;
        LPC_PINCON->PINSEL4 |= 0x0000000A;   /* Enable RxD1 P2.1, TxD1 P2.0 */

        /* By default, the PCLKSELx value is zero, thus, the PCLK for
        all the peripherals is 1/4 of the SystemFrequency. */
        /* Bit 8,9 are for UART1 */
        pclkdiv = (LPC_SC->PCLKSEL0 >> 8) & 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_UART1->LCR = 0x83;           /* 8 bits, no Parity, 1 Stop bit */
        Fdiv = ( pclk / 16 ) / baudrate ;       /*baud rate */
    LPC_UART1->DLM = Fdiv / 256;
    LPC_UART1->DLL = Fdiv % 256;
        LPC_UART1->LCR = 0x03;               /* DLAB = 0 */
    LPC_UART1->FCR = 0x07;           /* Enable and reset TX and RX FIFO. */

        NVIC_EnableIRQ(UART1_IRQn);

    LPC_UART1->IER = IER_RBR | IER_THRE | IER_RLS;   /* Enable UART1 interrupt */
    return (TRUE);
  }
  return( FALSE );
}

Reply

0 John Linq over 11 years ago in reply to dhanaraj shanmugam

\mcb1700.code_.bundle.lpc17xx.keil_\keil_examples\UART

/****************************************************************************
 *   $Id:: uart.c 5751 2010-11-30 23:56:11Z usb00423                        $
 *   Project: NXP LPC17xx UART example
 *
 *   Description:
 *     This file contains UART code example which include UART initialization,
 *     UART interrupt handler, and APIs for UART access.
 *
 ****************************************************************************
 * Software that is described herein is for illustrative purposes only
 * which provides customers with programming information regarding the
 * products. This software is supplied "AS IS" without any warranties.
 * NXP Semiconductors assumes no responsibility or liability for the
 * use of the software, conveys no license or title under any patent,
 * copyright, or mask work right to the product. NXP Semiconductors
 * reserves the right to make changes in the software without
 * notification. NXP Semiconductors also make no representation or
 * warranty that such application will be suitable for the specified
 * use without further testing or modification.
****************************************************************************/

/*****************************************************************************
** Function name:               UARTInit
**
** Descriptions:                Initialize UART port, setup pin select,
**                                              clock, parity, stop bits, FIFO, etc.
**
** parameters:                  portNum(0 or 1) and UART baudrate
** Returned value:              true or false, return false only if the
**                                              interrupt handler can't be installed to the
**                                              VIC table
**
*****************************************************************************/
uint32_t UARTInit( uint32_t PortNum, uint32_t baudrate )
{
  uint32_t Fdiv;
  uint32_t pclkdiv, pclk;

  if ( PortNum == 0 )
  {
        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;
        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_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 (TRUE);
  }
  else if ( PortNum == 1 )
  {
        LPC_PINCON->PINSEL4 &= ~0x0000000F;
        LPC_PINCON->PINSEL4 |= 0x0000000A;   /* Enable RxD1 P2.1, TxD1 P2.0 */

        /* By default, the PCLKSELx value is zero, thus, the PCLK for
        all the peripherals is 1/4 of the SystemFrequency. */
        /* Bit 8,9 are for UART1 */
        pclkdiv = (LPC_SC->PCLKSEL0 >> 8) & 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_UART1->LCR = 0x83;           /* 8 bits, no Parity, 1 Stop bit */
        Fdiv = ( pclk / 16 ) / baudrate ;       /*baud rate */
    LPC_UART1->DLM = Fdiv / 256;
    LPC_UART1->DLL = Fdiv % 256;
        LPC_UART1->LCR = 0x03;               /* DLAB = 0 */
    LPC_UART1->FCR = 0x07;           /* Enable and reset TX and RX FIFO. */

        NVIC_EnableIRQ(UART1_IRQn);

    LPC_UART1->IER = IER_RBR | IER_THRE | IER_RLS;   /* Enable UART1 interrupt */
    return (TRUE);
  }
  return( FALSE );
}

Children

0 saravanan g over 11 years ago in reply to John Linq

Dear Friends

Thank for your replies. i have datasheet,usermanual,keil sample code etc see here i used UART based sensor. that datasheet was gave 4800 baud ,8data bytes,1stop bit for receive that values

first i tried in hyperterminal everything is fine i modify the keil receiver code. according to that LPC_UART0->LCR = 0xb8. i got data but that value was different compare than microcontroller
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