lpc_uart.c

深圳优龙公司LPC2148开发板（与iar公司开发板基本相同）的原理图和配套样例程序

/*************************************************************************
 *
 *    Used with ICCARM and AARM.
 *
 *    (c) Copyright IAR Systems 2003
 *
 *    File name   : LPC_Uart.c
 *    Description : Define API for UART
 *
 *    History :
 *    1. Data: July 13, 2004											  
 *  	 Author: Shawn Zhang													
 *  	 Description: Create the basic function    
 *
 *    2. Data: August 09, 2004  											
 *  	 Author: Shawn Zhang													
 *  	 Description: Integrate two method :- by polling and by interrupt, user 
 *			  could select it.
 *
 *    3. Data: August 17, 2004  											
 *  	 Author: Shawn Zhang													
 *  	 Description:  1) Repair the bug about Tx ring buffer.
 *	 		   2) Repair the bug about ReadTxBuf function and ISR.
 *
 *    4. Data   	 : Oct 9, 2004 
 *  	 Author 	 : Stanimir Bonev
 *  	 Description : Modify some function and interface  
 *
 *    $Revision: 1.1 $
 **************************************************************************/

#include "LPC_Uart.h"

// Define globe variable
LPC_Uart_Config_t Uart0Config =
{
	BD38400, WordLength8, false, false, ParitySelOdd, false, true, FIFORXLEV2, IER_RBR | IER_RLS, INTERRUPT_MODE, 
};

LPC_Uart_Config_t Uart1Config =
{
	BD38400, WordLength8, false, false, ParitySelOdd, false, true, FIFORXLEV2, IER_RBR | IER_RLS, INTERRUPT_MODE, 
};

/*************************************************************************
 * Function Name: UART_InitUartBuf
 * Parameters: LPC_Uart_Buffer_t *pUartBuf
 * Return: void
 *
 * Description: Initialize Rx & Tx buffer, which is used when adopting interrupt method
 *  
 *************************************************************************/
void UART_InitUartBuf( LPC_Uart_Buffer_t* pUartBuf )
{
	pUartBuf->RxHeadPoint = 0;
	pUartBuf->RxTailPoint = 0;

	pUartBuf->TxHeadPoint = 0;
	pUartBuf->TxTailPoint = 0;

	pUartBuf->RxCount = 0;
	pUartBuf->TxCount = 0;

	pUartBuf->RxFlag = 0;
}

/*************************************************************************
 * Function Name: UART_Init
 * Parameters: LPC_UartChanel_t DevNum
 * 			
 * Return: int 
 *  		   	0: sucess
 *		1: fail
 * Description: Initialize Uart, configure baut rate, frame format and FIFO
 *  
 *************************************************************************/
int UART_Init( LPC_UartChanel_t DevNum )
{
	unsigned long Divisor, Frame, FIFO;
	LPC_Uart_Config_t* pConfig;

	if ( DevNum == UART0 )
		pConfig = &Uart0Config;
	else
		pConfig = &Uart1Config;

	if ( ( pConfig->BaudRate == 0 ) || ( pConfig->BaudRate > BD115200 ) )
		return 0;

	// baut rate
	Divisor = ( SYS_GetFpclk() >> 4 ) / pConfig->BaudRate; // Divisor = pclk / (16*bautrate)

	// frame format
	Frame = pConfig->WordLenth;
	if ( pConfig->TwoStopBitsSelect )
		Frame |= ( 1 << LCR_STOPBITSEL_BIT );
	if ( pConfig->ParityEnable )
	{
		Frame |= ( 1 << LCR_PARITYENBALE_BIT );
		Frame |= ( pConfig->ParitySelect << LCR_PARITYSEL_BIT );
	}
	if ( pConfig->BreakEnable )
		Frame |= ( 1 << LCR_BREAKCONTROL_BIT );

	// FIFO
	if ( pConfig->FIFOEnable )
		FIFO = ( ( pConfig->FIFORxTriggerLevel & 0x3 ) << 6 ) | 0x1;

	// Method Mode
	if ( pConfig->MethodMode == INTERRUPT_MODE )
		UART_InitUartBuf( &pConfig->UartBuffer );
	if ( DevNum == UART0 )
	{
		// Set baut rate
		U0LCR_bit.DLAB = true;	// DLAB = 1
		U0DLM = Divisor >> 8;
		U0DLL = Divisor;

		// Set frame format
		U0LCR = Frame;			// DLAB = 0

		// Set FIFO
		U0FCR = FIFO;

		// Set Interrupt Enable Register
		U0IER = pConfig->InterruptEnable & 0x5;

		// Enable TxD0 and RxD0, bit 0~3=0101
		//    PINSEL0 |= 0x05;
		PINSEL0_bit.P0_0 = 0x1;
		PINSEL0_bit.P0_1 = 0x1;
	}
	else if ( DevNum == UART1 )
	{
		// Set baut rate
		U1LCR_bit.DLAB = true;  	// DLAB = 1
		U1DLM = Divisor >> 8;
		U1DLL = Divisor & 0xff;

		// Set frame format
		U1LCR = Frame;  			// DLAB =0

		/* Set FIFO */
		U1FCR = FIFO;

		// Set Interrupt Enable Register
		U1IER = pConfig->InterruptEnable & 0x5;

		// Enable TxD0 and RxD0, bit 16~19=0101
		//    PINSEL0 |= 0x50000;
		PINSEL0_bit.P0_8 = 0x1;
		PINSEL0_bit.P0_9 = 0x1;
	}
	else
		return 1;
	return 0;
}


/*************************************************************************
 * Function Name: UART_PutCharByPolling
 * Parameters: LPC_UartChanel_t DevNum
 * 		   char ch
 * Return: void
 *
 *
 * Description: Send character by polling LSR register
 *  
 *************************************************************************/
void UART_PutCharByPolling( LPC_UartChanel_t DevNum , char ch )
{
	if ( DevNum == UART0 )
	{
		if( ch == '\n' )
		{
			while ( !U0LSR_bit.THRE );
			U0THR = '\r';
		}
					
		while ( !U0LSR_bit.THRE );
		U0THR = ch;
	}
	else
	{
		if( ch == '\n' )
		{
			while ( !U1LSR_bit.THRE );
			U1THR = '\r';
		}
	
		while ( !U1LSR_bit.THRE );
		U1THR = ch;
	}
}

/*************************************************************************
 * Function Name: UART_PutStringByPolling
 * Parameters: LPC_UartChanel_t DevNum
 * 		   char *Buf
 * Return: int : send character count
 *
 *
 * Description: Send a string by using polling method 
 *  
 *************************************************************************/
int UART_PutStringByPolling( LPC_UartChanel_t DevNum , char* Buf )
{
	char* pBuf = Buf ;
	int SendCount = 0;
	while ( *pBuf )
	{
		UART_PutCharByPolling( DevNum , *pBuf++ );
		++SendCount;
	}
	return ( SendCount );
}

/*************************************************************************
 * Function Name: UART_GetCharByPolling
 * Parameters: LPC_UartChanel_t DevNum
 * Return: char 
 *
 * Description: Receive a character from Uart by polling LSR register
 *  
 *************************************************************************/
char UART_GetCharByPolling( LPC_UartChanel_t DevNum )
{
	if ( DevNum == UART0 )
	{
		while ( !U0LSR_bit.DR );
		return ( U0RBR );
	}
	while ( !U1LSR_bit.DR );
	return ( U1RBR );
}

/*************************************************************************
 * Function Name: UART_GetCharByPolling
 * Parameters: LPC_UartChanel_t DevNum
 * Return: char 
 *
 * Description: Receive a character from Uart by polling LSR register
 *  
 *************************************************************************/
char UART_GetKeyByPolling( LPC_UartChanel_t DevNum )
{
	if ( DevNum == UART0 )
	{
		if ( U0LSR_bit.DR )
			return ( U0RBR );
		else
			return 0 ;
	}

	if ( U1LSR_bit.DR )
		return ( U1RBR );
	else
		return 0 ;
}

/*************************************************************************
 * Function Name: UART_PutStringByInterrupt
 * Parameters: LPC_UartChanel_t DevNum
 *		   char *Buf
 * Return: int : send character count
 *
 * Description: Send a string into Uart Buffer. 
 * 		Then Uart will send buffer data in its IRQ subroutine.
 *  
 *************************************************************************/
int UART_PutStringByInterrupt( LPC_UartChanel_t DevNum , char* Buf )
{
	char* pBuf = Buf, ch;
	
	LPC_Uart_Buffer_t* pUartBuf;
	int SendCount = 0;

	unsigned long IntFlagsHold;

	if ( DevNum == UART0 )
		pUartBuf = &Uart0Config.UartBuffer;
	else
		pUartBuf = &Uart1Config.UartBuffer;

	while ( *pBuf )
	{
		// if FIFO is full pending here, wait for send characters
		if ( pUartBuf->TxCount >= TXBUFSIZE )
		{
			break;
		}
		
		ch = *pBuf & 0xff;    
		pUartBuf->TxBuf[pUartBuf->TxTailPoint] = ch;
		pUartBuf->TxTailPoint = ( pUartBuf->TxTailPoint + 1 ) % TXBUFSIZE;
		IntFlagsHold = disable_IRQ();
		pUartBuf->TxCount++;
		restore_IRQ( IntFlagsHold );
		SendCount++;
		pBuf++;
	}