i2c_drv.c

一款车载DVD的车机源程序（正在生成中的哦）

/***************************************************************************
Project  :  Car two ting dvd System
Compiler :  ST7 HiCross C (HiWARE)
Module   :  autos.c 
Version  :  V 1.0
Created  :  24 11, 2005
Author   :  tomi / SA
Description
         -  I2c.  
Modified
		 - tomi
***************************************************************************/
#include "I2c_drv.h"
#include "Libr.h"
#include "St72321.h"
#include "IOport.h"
#include "TW101reg.h"

static void StartCondition(void);
static void StopCondition(void);
static unsigned char Send_Byte(unsigned char cData);
static unsigned char Read_Byte(unsigned char cNum);
unsigned char I2CReadByte(unsigned char cDevAddr, unsigned char cReg);
unsigned char I2CReadByte_no_sub(unsigned char cDevAddr);
unsigned char I2CWriteByte(unsigned char cDevAddr, unsigned char cReg, unsigned char cData);
unsigned char I2CReadBytes(unsigned char cDevAddr, unsigned char cReg, unsigned char *pString, unsigned char cNum);
unsigned char I2CWriteByte_noAddrsss(unsigned char cDevAddr,unsigned char cData);
unsigned char I2CWrite_nBytes(unsigned char cDevAddr,unsigned char *buff,unsigned char num);
/**********************************************************
Function:I2c start command
**********************************************************/
static void StartCondition(void)
{
    unsigned char ix;
    unsigned char cTWtrytime=0;
    while(++cTWtrytime)
    {

        Set_SDA_High;
        Set_SCL_High;        /* make sure two line is release */
        for(ix = 0; ix < TWD_LONG_TIME; ix++)
        { };  /* Delay 12us */

        Set_SDA_Low;
        for(ix = 0; ix < TWD_LONG_TIME; ix++)
        { };  /* Delay 12us */

        if((SCL_High)&&(SDA_Low))
            break;
    }

    for(ix = 0; ix < TWD_SHORT_TIME; ix++)
    { };  /* Delay 12us */
}
/**********************************************************
Function:I2c stop command
**********************************************************/
static void StopCondition(void)
{
    unsigned char ix;
   	unsigned char cTWtrytime=0;

    Set_SDA_Low;
    Set_SCL_High;
    for(ix = 0; ix < TWD_SHORT_TIME; ix++)
    { };  /* delay 12us */

    while(SCL_Low && ++cTWtrytime)
    { };

    for(ix = 0; ix < TWD_SHORT_TIME; ix++)
    { };  /* delay 12us */

    Set_SDA_High;
    for(ix = 0; ix < TWD_SHORT_TIME; ix++)
    { };  /* delay 12us */
}
/**********************************************************
Function:I2c send one byte to the slower
**********************************************************/
static unsigned char Send_Byte(unsigned char cData)
{
    unsigned char ix, j, cAcknowledge;
    unsigned char cTWtrytime=0;

    cAcknowledge = 0;

    for(ix = 0; ix < 8; ix++)
    {
        Set_SCL_Low;
        for(j = 0; j < TWD_SHORT_TIME; j++)
        { };

        if(cData&0x80)Set_SDA_High;
		else Set_SDA_Low;
		cData<<=1;

        for(j = 0; j < TWD_SHORT_TIME; j++)
        { };

        Set_SCL_High;
        while(SCL_Low && ++cTWtrytime)
        { };

        for(j = 0; j < TWD_SHORT_TIME; j++)
        { };
    }
    for(j = 0; j < TWD_SHORT_TIME; j++)
    { };

    Set_SCL_Low;
    for(j = 0; j < TWD_SHORT_TIME; j++)
    { };

    Set_SDA_High;                /* release data line for acknowledge */
    for(j = 0; j < TWD_SHORT_TIME; j++)
    { };

	SET_SDA_AS_INPUT;	/*This is tomi new adding,because the ST IO not same as the 8051*/
	for(j = 0; j < TWD_SHORT_TIME; j++)
    { };
	
    Set_SCL_High;                /* Send a clock for Acknowledge */
    while(SCL_Low)
    { };
    for(j = 0; j < TWD_SHORT_TIME; j++)
    { };

    if(SDA_High) 
       cAcknowledge = 1; /* No Acknowledge */
    Set_SCL_Low;                   /* Finish Acknoledge */
    for(j = 0; j < TWD_SHORT_TIME; j++)
    { };

    SET_SDA_AS_OUTPUT;	/*This is tomi new adding,because the ST IO not same as the 8051*/
    for(j = 0; j < TWD_SHORT_TIME; j++)
    { };

    return(cAcknowledge);
}
/**************************************************************
Function:Read a byte from slower with a acknowledge bit
**************************************************************/
static unsigned char Read_Byte(unsigned char cNum)
{
    unsigned char ix, j;
    unsigned char cRetval=0;
	SET_SDA_AS_INPUT;	/*This is tomi new adding,because the ST IO not same as the 8051*/
	for(j=0;j<TWD_SHORT_TIME;j++)
		{};
	
    for(ix=0;ix<8;ix++){
          Set_SCL_High;
          while(SCL_Low){};
          for(j=0;j<TWD_SHORT_TIME;j++){};
          cRetval = (SDA_High)? (cRetval|(1<<(7-ix))):cRetval ;  /* MSB First */
	  Set_SCL_Low;
     }

     if(cNum==1)
     	Set_SDA_High;
     else
		Set_SDA_Low;
     //SDA = (cNum==1) 1:0;
     Set_SCL_High;
     while(SCL_Low){};
     for(j = 0; j < TWD_SHORT_TIME; j++)
     { };

    Set_SCL_Low;
    
	SET_SDA_AS_OUTPUT;	/*This is tomi new adding,because the ST IO not same as the 8051*/
	for(j = 0; j < TWD_SHORT_TIME; j++)
     { };
	
    Set_SDA_High;
    for(j = 0; j < TWD_SHORT_TIME; j++)
    { };

    return cRetval;
}
/*******************************************************************
Function:Maker read one byte from the slower's appointed address
*******************************************************************/
unsigned char I2CReadByte(unsigned char cDevAddr, unsigned char cReg)
{
    unsigned char cResult = 0;

	/* write reg offset */
    StartCondition();
    if(Send_Byte(cDevAddr))
	return 0;  // Write address
    if(Send_Byte(cReg))
	return 0;

    /* read data */
    StartCondition();
    if (Send_Byte(cDevAddr | 0x01)) // Read address
	return 0;
    cResult = Read_Byte(1);

    StopCondition();
    return cResult;
}
/*******************************************************************
Function:
*******************************************************************/
unsigned char I2CReadByte_no_sub(unsigned char cDevAddr)
{
	unsigned char cResult = 0;
	/* write reg offset */
    StartCondition();
    if(Send_Byte(cDevAddr))
	return 0;  // Write address

	/* read data */
    StartCondition();
    if (Send_Byte(cDevAddr | 0x01)) // Read address
	return 0;
    cResult = Read_Byte(1);

    StopCondition();
    return cResult;
}
/*******************************************************************
Function:Maker send one byte to the slower's appointed address
*******************************************************************/
unsigned char I2CWriteByte(unsigned char cDevAddr, unsigned char cReg, unsigned char cData)
{
	/* start condition */
    StartCondition();
  	cDevAddr &= 0xFE;   // Force WRITE address
    /* send device ID and write data */
    if(!Send_Byte(cDevAddr))
    {
        if(!Send_Byte(cReg))
        {
            if(!Send_Byte(cData))
            {
                StopCondition();
                return(0);      /* success */
            }
        }
    }
    StopCondition();
    return(1);
}
/*********************************************************************
Function:Read more than one byte from the slower to the appointed address
*********************************************************************/
unsigned char I2CReadBytes(unsigned char cDevAddr, unsigned char cReg, unsigned char *pString, unsigned char cNum)
{
	/* write reg offset */
	StartCondition();
  if(Send_Byte(cDevAddr))
		return 0;  // Write address
  if(Send_Byte(cReg))
		return 0;

	/* read data */
  StartCondition();
  if (Send_Byte(cDevAddr | 0x01)) // Read address
		return 0;
	while(cNum)
  {
  	*pString++ = Read_Byte(cNum);
		cNum--;
	}

 	StopCondition();
  return 1;
}
/*********************************************************************
Function:Send one byte to the slower no the appointed address
*********************************************************************/
unsigned char I2CWriteByte_noAddrsss(unsigned char cDevAddr,unsigned char cData)
{
	/* start condition */
    StartCondition();
  	cDevAddr &= 0xFE;   // Force WRITE address
    /* send device ID and write data */
    if(!Send_Byte(cDevAddr))
    {
		if(!Send_Byte(cData))
        {
        	StopCondition();
            return(0);      /* success */
        }
    }
    StopCondition();
    return(1);
	
}
/****************************************************************
Function:I2c write n bytes
****************************************************************/
unsigned char I2CWrite_nBytes(unsigned char cDevAddr,unsigned char *buff,unsigned char num)
{
	unsigned char i;
	unsigned char Ack;
	/* start condition */
    StartCondition();
	cDevAddr &= 0xFE;   // Force WRITE address
    /* send device ID and write data */
    Ack = Send_Byte(cDevAddr);
    if(!Ack)
    	{
		for (i=0; i<num; i++)
		{
			if (!Ack)
			Ack = Send_Byte (*buff++);
		}
		StopCondition();
        return(0);      /* success */
    	}
	StopCondition();
    return(1);
}
/***********************************************************
Function:I2C write have sub address and write n bytes
***********************************************************/
unsigned char I2C_write_sub(unsigned char cDevAddr,unsigned char sub_addr,unsigned char *buff,unsigned char num)
{
	unsigned char i;
	unsigned char Ack;
	/* start condition */
    StartCondition();
	cDevAddr &= 0xFE;   // Force WRITE address
    /* send device ID and write data */
    Ack = Send_Byte(cDevAddr);
    if(!Ack)
    	Ack = Send_Byte(sub_addr);
    if(!Ack)
    	{
		for (i=0; i<num; i++)
		{
			if (!Ack)
			Ack = Send_Byte (*buff++);
		}
		StopCondition();
        return(0);      /* success */
    	}
	StopCondition();
    return(1);
}
/***********************************************************
Function:Configure the T100's A0/A1 IO port
***********************************************************/
void OSDCfgWr(unsigned char  index,unsigned char dat)
{
 I2CWriteByte(TW101,OSD_CFG_INDEX,index);
 I2CWriteByte(TW101,OSD_CFG_DATA,dat);
}

unsigned char twdWr_Burst_A(unsigned char cReg)
{
    StartCondition();
    if(!Send_Byte(TW101))
    {
        if(!Send_Byte(cReg))
        {
            return(0);               //
        }
    }
    return(1);                  //
}

void twdWr_Burst_D(unsigned char cData)
{
    unsigned char ix;

    for(ix = 0; ix < 8; ix++)
    {
        Set_SCL_Low;
        if(cData&0x80)Set_SDA_High;
		else Set_SDA_Low;
		cData<<=1;
        Set_SCL_High;
    }
    Set_SCL_Low;
    Set_SDA_High;                /* release data line for acknowledge */
    Set_SCL_High;                /* Send a clock for Acknowledge */
//    if(SDA_High) cAcknowledge = 1; /* No Acknowledge */
    Set_SCL_Low;                   /* Finish Acknoledge */

//    return(cAcknowledge);
}
void twdWr_Burst_P(void)
{
    StopCondition();
}

void twdDelay(unsigned short wLoops)
{
	unsigned short wTemp;

    while (wLoops--) {
	    wTemp = 1000/6;	// one loop below takes about 11 us
        while (wTemp--);
    }
}