uart.c

通过讨论常见的串口软件使用的方法

/*----------------------------------------------------------------------------------
File: 					uart.c
Author: 				Qiu Peng   [[e-mail]]
Note:					UART driver for S3C44B0X
Create Date:			2004.7.25
Last Modified:			2004.7.28
-----------------------------------------------------------------------------------*/

#include "../inc/uart.h"

char TxBuf[TxBufLen], RxBuf[RxBufLen];
char *inTxBuf, *outTxBuf, *inRxBuf, *outRxBuf;

//for statistic
int	UartTxCount, UartRxCount;

//use Uart0 or Uart1, default for the Uart0
static int UartInUse = 0;

/*------------------------------------------------------------------------------
Function:	Uart_Init
Note:		S3C44B0X UART(0,1) initial
In:			
		1. mclk:  used for count UBRDIVn, 0 to use CPU MCLK	
		2. baud:  Uart baud rate
		example: Uart_Init(0, 9600)
Out:		None
Date:		2004.7.25  /  2004.7.25 
-------------------------------------------------------------------------------*/
void Uart_Init_2(int mclk, int baud)
{
	int i;
    if (mclk == 0)
		mclk=MCLK;

	//UART0		
    rUFCON0 = 0x0;     	//FIFO disable
    rUMCON0 = 0x0;		//AFC Disable
    rULCON0 = 0x3;     	//Normal,No parity,1 stop,8 bit
    rUCON0 = 0x245;    //rx=edge,tx=level,disable timeout int.,enable rx error int.,normal,interrupt or polling
    rUBRDIV0 = ( (int)(mclk/16./baud + 0.5) -1 );	//see S3C44B0X datasheet Ch10 UART p10-18
    
	//UART1
    rUFCON1=0x0;
    rUMCON1=0x0;
    rULCON1=0x3;
    rUCON1=0x245;
    rUBRDIV1=( (int)(mclk/16./baud + 0.5) -1 );

	//pISR_UTXD0=(unsigned)UartTx;
	
	UartTxCount = 0;
	UartRxCount = 0;
	
    for(i = 0; i < 100; i++);		//do some delay
}


/*------------------------------------------------------------------------------
Function:	Uart_InitBuffer
Note:		Uart Tx and Rx buffer init
In:			None
Out:		None
Date:		2004.7.25  /  2004.7.25 
-------------------------------------------------------------------------------*/
void Uart_InitBuffer(void)
{
	//at first, the in/out pointers both in the base of their buffer
	inTxBuf = TxBuf;
	outTxBuf = TxBuf;
	
	inRxBuf = RxBuf;
	outRxBuf = RxBuf;
	
	UartTxCount = 0;
	UartRxCount = 0;
}


/*------------------------------------------------------------------------------
Function:	Uart_Select
Note:		S3C44B0X has 2 UARTs. to choose one
In:			UartNo: 0, Uart0;  1, Uart1
Out:		None
Date:		2004.7.25  /  2004.7.25 
-------------------------------------------------------------------------------*/
void Uart_select(int UartNo)
{
	if (UartNo == 0)
		UartInUse = 0;
	else 
		UartInUse = 1;
}


/*------------------------------------------------------------------------------
Function:	Uart_TxStart
Note:		In order to enter Tx INT, write a byte(fisrt of TxBuf) to Tx BUF.
In:			None
Out:		None
Date:		2004.7.25  /  2004.7.28 
-------------------------------------------------------------------------------*/
void Uart_TxStart(void)
{
	if (outTxBuf == inTxBuf)	//TxBuf empty
	{
		return;
	}	
	
	if (UartInUse == 0)
	{
		if (rUTRSTAT0 & 0x2)	//if Transmit buffer is empty, Tx not start.
			WrUTXH0(*outTxBuf);	
		else
			return;
	}
	else
	{
		if (rUTRSTAT1 & 0x2)	//if Transmit buffer is empty, Tx not start.
			WrUTXH0(*outTxBuf);	
		else
			return;
	}
	
	outTxBuf++;			//point to next data that will be sent
	
	if (outTxBuf == (TxBuf+TxBufLen))		//beyond the range
		outTxBuf = TxBuf;
	
	UartTxCount++;
}


/*------------------------------------------------------------------------------
Function:	UartTx
Note:		called by real Tx ISR, send data and do buffer process
In:			None
Out:		None
Date:		2004.7.25  /  2004.7.25 
-------------------------------------------------------------------------------*/
void UartTx(void)
{	
	
	if (outTxBuf == inTxBuf)	//TxBuf empty
	{
		//TIflag = 0;
		return;
	}	
	
	if (UartInUse == 0)
	{
		WrUTXH0(*outTxBuf);		//from TxBuf, write a byte to Tx reg. see 44b.h
		rI_ISPC |= BIT_UTXD0;		//clear pending bit
	}
	else
	{
		WrUTXH1(*outTxBuf);
		rI_ISPC |= BIT_UTXD1;		//clear pending bit
	}
	
	outTxBuf++;			//point to next data that will be sent
	
	if (outTxBuf == (TxBuf+TxBufLen))		//beyond the range
		outTxBuf = TxBuf;
	
	UartTxCount++;
}


/*------------------------------------------------------------------------------
Function:	UartRx
Note:		called by real Rx ISR, receive a byte to RxBuf
In:			None
Out:		None
Date:		2004.7.25  /  2004.7.25 
-------------------------------------------------------------------------------*/
void UartRx(void)
{
	char *t;
	
	t = inRxBuf;
	t++;
	if (t == (RxBuf+RxBufLen))
		t = RxBuf;
		
	if (t==outRxBuf)		//RxBuf full, no receive
		return;
	
	if (UartInUse == 0)
		*inRxBuf = RdURXH0();
	else
		*inRxBuf = RdURXH1();
		
	inRxBuf = t;
	UartRxCount++;
}


/*------------------------------------------------------------------------------
Function:	Uart_PrintChar
Note:		write a byte to TxBuf
In:			ch: the byte to send
Out:		None
Date:		2004.7.25  /  2004.7.25 
-------------------------------------------------------------------------------*/
void Uart_PrintChar(char ch)
{
	char *t;
	
	t = inTxBuf;
	t++;
	
	if (t == (TxBuf+TxBufLen))
		t = TxBuf;
	
	if (t == outTxBuf)		//TxBuf full
		return;				//no send
		
	*inTxBuf = ch;
	inTxBuf = t;
	
	Uart_TxStart();				//Tx begin
		
}


/*------------------------------------------------------------------------------
Function:	Uart_PrintStr
Note:		put a string to TxBuf
In:			pt: the pointer of the string
Out:		None
Date:		2004.7.25  /  2004.7.28 
-------------------------------------------------------------------------------*/
void Uart_PrintStr(char *pt)
{
	char *t, *p;
	
	t = inTxBuf;
	p = pt;
	
	while (*p != '\0')				//put into TxBuf one by one
	{
		t++;
		if (t == (TxBuf+TxBufLen))
			t = TxBuf;
		
		if (t == outTxBuf)		//TxBuf full
			return;				//no send 
		
		*inTxBuf = *p++;
		inTxBuf = t;
	}
	
	Uart_TxStart();				//Tx begin
}


/*------------------------------------------------------------------------------
Function:	Uart_Printf
Note:		put a string to TxBuf, like printf on PC platform.
In:			fmt: the number is uncertain.
Out:		None
Date:		2004.7.25  /  2004.7.25 
-------------------------------------------------------------------------------*/
void Uart_printf(char *fmt,...)
{
	va_list ap;
    char string[512];

    va_start(ap,fmt);
    vsprintf(string,fmt,ap);
    Uart_PrintStr(string);
    va_end(ap);
    
}

/*------------------------------------------------------------------------------
Function:	Uart_GetStr
Note:		get a string, then send message to OS TaskShell to parse.
In:			str
Out:		str:	received string. 
Date:		2004.7.25  /  2004.7.25 
-------------------------------------------------------------------------------*/
int  Uart_GetStr(char *str)
{
	char *p;
	p = str;	
	return 0;
}