uart.c

NXP LPC2378 UART Demo

/*****************************************************************************
 *   uart.c:  UART API file for NXP LPC23xx/24xx Family Microprocessors
 *
 *   Copyright(C) 2006, NXP Semiconductor
 *   All rights reserved.
 *
 *   History
 *   2006.07.12  ver 1.00    Prelimnary version, first Release
 *
******************************************************************************/
#include "LPC23xx.h"                        /* LPC23xx/24xx definitions */
#include "type.h"
#include "target.h"
#include "irq.h"
#include "uart.h"

volatile DWORD UART0Status, UART1Status;
volatile BYTE UART0TxEmpty = 1, UART1TxEmpty = 1;
volatile BYTE UART0Buffer[BUFSIZE], UART1Buffer[BUFSIZE];
volatile DWORD UART0Count = 0, UART1Count = 0;

/*****************************************************************************
** Function name:		UART0Handler
**
** Descriptions:		UART0 interrupt handler
**
** parameters:			None
** Returned value:		None
** 
*****************************************************************************/
void UART0Handler (void) __irq 
{
  BYTE IIRValue, LSRValue;
  BYTE Dummy = Dummy;

  IENABLE;				/* handles nested interrupt */	
  IIRValue = U0IIR;
    
  IIRValue >>= 1;			/* skip pending bit in IIR */
  IIRValue &= 0x07;			/* check bit 1~3, interrupt identification */
  if ( IIRValue == IIR_RLS )		/* Receive Line Status */
  {
	LSRValue = U0LSR;
	/* Receive Line Status */
	if ( LSRValue & (LSR_OE|LSR_PE|LSR_FE|LSR_RXFE|LSR_BI) )
	{
	  /* There are errors or break interrupt */
	  /* Read LSR will clear the interrupt */
	  UART0Status = LSRValue;
	  Dummy = U0RBR;		/* Dummy read on RX to clear 
							interrupt, then bail out */
	  IDISABLE;
	  VICVectAddr = 0;		/* Acknowledge Interrupt */
	  return;
	}
	if ( LSRValue & LSR_RDR )	/* Receive Data Ready */			
	{
	  /* If no error on RLS, normal ready, save into the data buffer. */
	  /* Note: read RBR will clear the interrupt */
	  UART0Buffer[UART0Count] = U0RBR;
	  UART0Count++;
	  if ( UART0Count == BUFSIZE )
	  {
		UART0Count = 0;		/* buffer overflow */
	  }	
	}
  }
  else if ( IIRValue == IIR_RDA )	/* Receive Data Available */
  {
	/* Receive Data Available */
	UART0Buffer[UART0Count] = U0RBR;
	UART0Count++;
	if ( UART0Count == BUFSIZE )
	{
	  UART0Count = 0;		/* buffer overflow */
	}
  }
  else if ( IIRValue == IIR_CTI )	/* Character timeout indicator */
  {
	/* Character Time-out indicator */
	UART0Status |= 0x100;		/* Bit 9 as the CTI error */
  }
  else if ( IIRValue == IIR_THRE )	/* THRE, transmit holding register empty */
  {
	/* THRE interrupt */
	LSRValue = U0LSR;		/* Check status in the LSR to see if
							valid data in U0THR or not */
	if ( LSRValue & LSR_THRE )
	{
	  UART0TxEmpty = 1;
	}
	else
	{
	  UART0TxEmpty = 0;
	}
  }
    
  IDISABLE;
  VICVectAddr = 0;		/* Acknowledge Interrupt */
}

/*****************************************************************************
** Function name:		UART1Handler
**
** Descriptions:		UART1 interrupt handler
**
** parameters:			None
** Returned value:		None
** 
*****************************************************************************/
void UART1Handler (void) __irq 
{
  BYTE IIRValue, LSRValue;
  BYTE Dummy = Dummy;

  IENABLE;				/* handles nested interrupt */	
  IIRValue = U1IIR;
    
  IIRValue >>= 1;			/* skip pending bit in IIR */
  IIRValue &= 0x07;			/* check bit 1~3, interrupt identification */
  if ( IIRValue == IIR_RLS )		/* Receive Line Status */
  {
	LSRValue = U1LSR;
	/* Receive Line Status */
	if ( LSRValue & (LSR_OE|LSR_PE|LSR_FE|LSR_RXFE|LSR_BI) )
	{
	  /* There are errors or break interrupt */
	  /* Read LSR will clear the interrupt */
	  UART1Status = LSRValue;
	  Dummy = U1RBR;		/* Dummy read on RX to clear 
							interrupt, then bail out */
	  IDISABLE;
	  VICVectAddr = 0;		/* Acknowledge Interrupt */
	  return;
	}
	if ( LSRValue & LSR_RDR )	/* Receive Data Ready */			
	{
	  /* If no error on RLS, normal ready, save into the data buffer. */
	  /* Note: read RBR will clear the interrupt */
	  UART1Buffer[UART1Count] = U1RBR;
	  UART1Count++;
	  if ( UART1Count == BUFSIZE )
	  {
		UART1Count = 0;		/* buffer overflow */
	  }	
	}
  }
  else if ( IIRValue == IIR_RDA )	/* Receive Data Available */
  {
	/* Receive Data Available */
	UART1Buffer[UART1Count] = U1RBR;
	UART1Count++;
	if ( UART1Count == BUFSIZE )
	{
	  UART1Count = 0;		/* buffer overflow */
	}
  }
  else if ( IIRValue == IIR_CTI )	/* Character timeout indicator */
  {
	/* Character Time-out indicator */
	UART1Status |= 0x100;		/* Bit 9 as the CTI error */
  }
  else if ( IIRValue == IIR_THRE )	/* THRE, transmit holding register empty */
  {
	/* THRE interrupt */
	LSRValue = U1LSR;		/* Check status in the LSR to see if
								valid data in U0THR or not */
	if ( LSRValue & LSR_THRE )
	{
	  UART1TxEmpty = 1;
	}
	else
	{
	  UART1TxEmpty = 0;
	}
  }
    
  IDISABLE;
  VICVectAddr = 0;		/* Acknowledge Interrupt */
}

/*****************************************************************************
** Function name:		UARTInit
**
** Descriptions:		Initialize UART0 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
** 
*****************************************************************************/
DWORD UARTInit( DWORD PortNum, DWORD baudrate )
{
  DWORD Fdiv;

  if ( PortNum == 0 )
  {
	PINSEL0 = 0x00000050;       /* RxD0 and TxD0 */

    U0LCR = 0x83;		/* 8 bits, no Parity, 1 Stop bit */
    Fdiv = ( Fpclk / 16 ) / baudrate ;	/*baud rate */
    U0DLM = Fdiv / 256;							
    U0DLL = Fdiv % 256;
	U0LCR = 0x03;		/* DLAB = 0 */
    U0FCR = 0x07;		/* Enable and reset TX and RX FIFO. */

    if ( install_irq( UART0_INT, (void *)UART0Handler, HIGHEST_PRIORITY ) == FALSE )
    {
	  return (FALSE);
    }
   
    U0IER = IER_RBR | IER_THRE | IER_RLS;	/* Enable UART0 interrupt */
    return (TRUE);
  }
  else if ( PortNum == 1 )
  {
#if EA_BOARD_LPC24XX
	PINSEL7 |= 0x0000000F;	/* P3.16 TXD1, P3.17 RXD1 */
#else						/* Default is Keil MCB2300 board */							
	PINSEL0 |= 0x40000000;	/* Enable TxD1 P0.15 */
	PINSEL1 |= 0x00000001;	/* Enable RxD1 P0.16 */
#endif
    U1LCR = 0x83;		/* 8 bits, no Parity, 1 Stop bit */
    Fdiv = ( Fpclk / 16 ) / baudrate ;	/*baud rate */
    U1DLM = Fdiv / 256;							
    U1DLL = Fdiv % 256;
	U1LCR = 0x03;		/* DLAB = 0 */
    U1FCR = 0x07;		/* Enable and reset TX and RX FIFO. */

    if ( install_irq( UART1_INT, (void *)UART1Handler, HIGHEST_PRIORITY ) == FALSE )
    {
	  return (FALSE);
    }
   
    U1IER = IER_RBR | IER_THRE | IER_RLS;	/* Enable UART0 interrupt */
    return (TRUE);
  }
  return( FALSE ); 
}

/*****************************************************************************
** Function name:		UARTSend
**
** Descriptions:		Send a block of data to the UART 0 port based
**						on the data length
**
** parameters:			portNum, buffer pointer, and data length
** Returned value:		None
** 
*****************************************************************************/
void UARTSend( DWORD portNum, BYTE *BufferPtr, DWORD Length )
{
  if ( portNum == 0 )
  {
    while ( Length != 0 )
    {
	  /* THRE status, contain valid data */
	  while ( !(UART0TxEmpty & 0x01) );	
	  U0THR = *BufferPtr;
	  UART0TxEmpty = 0;	/* not empty in the THR until it shifts out */
	  BufferPtr++;
	  Length--;
	}
  }
  else
  {
	while ( Length != 0 )
    {
	  /* THRE status, contain valid data */
	  while ( !(UART1TxEmpty & 0x01) );	
	  U1THR = *BufferPtr;
	  UART1TxEmpty = 0;	/* not empty in the THR until it shifts out */
	  BufferPtr++;
	  Length--;
    }
  }
  return;
}

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