uart_dma.c

LPCXpresso1768

/****************************************************************************
 *   $Id:: uart_dma.c 5793 2010-12-02 23:08:27Z usb00423                    $
 *   Project: NXP LPC17xx UART DMA 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.
****************************************************************************/
#include "LPC17xx.h"
#include "type.h"
#include "uart_dma.h"

/*****************************************************************************
** 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_SC->PCONP |= (0x1<<3);
	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|(0x2<<6);		/* Enable and reset TX and RX FIFO. */
    return (TRUE);
  }
  else if ( PortNum == 1 )
  {
	LPC_SC->PCONP |= (0x1<<4);;
	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|(0x2<<6);		/* Enable and reset TX and RX FIFO. */
    return (TRUE);
  }
  return( FALSE ); 
}

/******************************************************************************
**                            End Of File
******************************************************************************/