iic.c

mc9s08aw60 RTC LCD PWM

#include  "config.h"
#include <stdio.h>

union
{
float f;
uchar c;
uint  i; 	
}IIC_union;


/******************************************************************************************/
//
/******************************************************************************************/
/*void delayXms(uint time) //延时xxms  time<744
{
  ulong i;
  for(i=29*time;i>0;i--){}
}  */
//================================================================= 
// Provide some data setup time to allow 
// SDA to stabilize in slave device 
// Completely arbitrary delay (10 cycles) 
//=================================================================  
void I2CSetupDelay() { asm NOP; asm NOP; } 
//================================================================= 
// Bit delay to provide (approximately) the desired 
// SCL frequency // Again, this is arbitrary (16 cycles) 
//================================================================= 
void I2CBitDelay() { asm NOP; asm NOP; asm NOP; asm NOP; asm NOP; } 
/*****************************************************************************************
//
//IIC读写子程序
//
******************************************************************************************/
bit   RW24XX(unsigned char *DataBuff,uchar ByteQuantity,uint Address,uchar ControlByte)
{

    unsigned char i=ERRORCOUNT;
	unsigned char      errorflag=1;

        IICStart();
        IICSendByte(0xA0);
        delayXms(10);
  		  IICSendByte((unsigned char)(Address>>8));
  		  delayXms(10);
  	    IICSendByte((unsigned char)Address);
  		  

      	IICStart();
    		IICSendByte(0XA1);
    		delayXms(10);
    		while(--ByteQuantity) {
    		  
      	*DataBuff++=IICReceiveByte();
      	delayXms(10);
    		}
	      IICStop();
	       errorflag=0;
	if(!(ControlByte&0x01))
	{
  		delayXms(20);
  	}
	return(errorflag);
}

//=================================================================
// A START condition is defined as a falling edge 
// on SDA while SCL is high 
//=================================================================
void I2CStartBit() {
    I2CPORT |= SCL; 
    I2CPORT |= SDA;
    SDA1=1;
    SCL1=1;
    SDA1=0;
    //I2CDIR |= SDA; 
    //I2CDIR |= SCL; 
    //I2CPORT &= ~SDA; 
    I2CBitDelay();
    //I2CPORT &= ~SCL;
    SCL1=0;
 } 
//=================================================================
// A STOP condition is defined as a rising edge 
// on SDA while SCL is high 
//=================================================================
void I2CStopBit() 
{ 
    I2CPORT &= ~SDA; 
    I2CPORT |= SCL; 
    I2CPORT |= SDA; 
    I2CBitDelay();
}
//=================================================================
//
//================================================================= 
void I2CTxByte(unsigned char ch) 
{
    unsigned char i; 
    for(i = 8;i >0;i--) 
    { 
      if((ch & 0x80)!=0) I2CPORT |= SDA; //Set the data bit value 
      else I2CPORT &= ~SDA; 
      I2CSetupDelay(); 
      I2CPORT |= SCL; 
      I2CBitDelay(); 
      I2CPORT &= ~SCL; 
      ch <<= 1; 
    } 
    I2CPORT |= SDA; 
    I2CDIR &= ~SDA; //Set SDA as input I2CSetupDelay(); 
    I2CPORT |= SCL; //Clock the line to get ACK 
    I2CBitDelay();
// 
    if((I2CPORT & SDA)==0) { 
    //Look for ACK from slave device 
        I2CPORT &= ~SCL; //Restore clock line 
        I2CDIR |= SDA; //SDA back as output 
    } 
    else 
    { 
    //No acknowledgment received from slave device 
    //Some error action can be performed here 
    //For now, just restore the bus 
        I2CPORT &= ~SCL; 
        I2CDIR |= SDA; 
    } 
} 
//================================================================= 
// I2CRxByte // Recieve the byte to Acc from the SDA pin 
// (Acc will not be restored on return) 
// Must be careful to change SDA values only while SCL is low, 
// otherwise a STOP or START could be implied 
//=================================================================
unsigned char I2CRxByte() 
{ 
    unsigned char i,ch=0; 
    I2CDIR &= ~SDA; 
    //Set the SDA as input 
    for(i = 8;i > 0;i--) 
    { ch <<= 1; 
    // I2CSetupDelay(); 
    //Wait a bit 
    I2CPORT |= SCL; //Clock it in 
    I2CSetupDelay(); //Wait a bit 
    if((I2CPORT & SDA)!=0) ch++; 
    I2CPORT &= ~SCL; //Restore clock to low state 
    I2CBitDelay(); 
    }// 
    I2CPORT &= ~SDA; 
    //SDA set low 
    I2CDIR |= SDA; 
    //Set SDA as output 
    I2CSetupDelay(); 
    I2CPORT |= SCL; //Clock the line to give    ACK 
    I2CBitDelay();// 
    I2CPORT &= ~SCL; 
    return ch; 
} 
 

/*****************************************************************************************
//
//启动总线
//
******************************************************************************************/
void IICStart(void)
{
    I2CPORT |= SCL; 
    I2CPORT |= SDA;
    SDA1=1;
    SCL1=1;
    SDA1=0;
    //I2CDIR |= SDA; 
    //I2CDIR |= SCL; 
    //I2CPORT &= ~SDA; 
    I2CBitDelay();
    //I2CPORT &= ~SCL;
    SCL1=0;
    /*
    I2CPORT |= SCL; 
    I2CPORT |= SDA; 
    I2CDIR |= SDA; 
    I2CDIR |= SCL; 
    I2CPORT &= ~SDA; 
    I2CBitDelay();
    I2CPORT &= ~SCL;
    */
/*
	SDA=1;
	asm(nop);
	asm(nop);
	SCL=1;
	PTCDD_PTCDD0=1;
  PTCDD_PTCDD1=1;
  asm(nop);
	asm(nop);
	SDA=0;
	asm(nop);
	asm(nop);
	asm(nop);
	asm(nop);
	asm(nop);
	SCL=0;
	asm(nop);
	asm(nop);  
	*/        
}
/******************************************************************************************
//
// 停止总线
//
******************************************************************************************/
void IICStop(void)
{
    SDA1=0;
    SCL1=1;
    SDA1=1;
    I2CBitDelay();
  /*
    I2CPORT &= ~SDA; 
    I2CPORT |= SCL; 
    I2CPORT |= SDA; 
    I2CBitDelay();
    */
/*
	SDA=0;
	asm(nop);
	asm(nop);
	SCL=1;
	asm(nop);
	asm(nop);
	SDA=1;
	asm(nop);
	asm(nop);
	asm(nop);
	asm(nop);
	asm(nop);
	*/
}
/******************************************************************************************
//
// 检查应答位
//
******************************************************************************************/
bit IICRecAck(void)
{
  unsigned char CY=0;
   /*
	SDA=1;
	PTCDD_PTCDD1=0;
	asm(nop);
	asm(nop);
	SCL=1;
	asm(nop);
	asm(nop);
	asm(nop);
	asm(nop);
	asm(nop); 
	CY=SDA;	 
	asm(nop);
	asm(nop);
	PTCDD_PTCDD1=1;
	*/
	return(CY);
}
/******************************************************************************************
//
// 产生应答
//
*******************************************************************************************/
void abcIICAck(void)//
{
/*
  PTCDD_PTCDD1=1;
	SDA=0;
  asm(nop);
  asm(nop);
	SCL=1;
  asm(nop);
  asm(nop);
	SCL=0;
  asm(nop);
  asm(nop);
  asm(nop);
	asm(nop);
	asm(nop);
	SDA=1;
	*/
}
/******************************************************************************************
//
// 不产生应答
//
******************************************************************************************/
void IICNoAck(void)
{
/*
	PTCDD_PTCDD1=1;
	SDA=1;
  asm(nop);
  asm(nop);
	SCL=1;
	asm(nop);
	asm(nop);
	asm(nop);
	asm(nop);
	asm(nop);
	SCL=0;
	*/
}
/******************************************************************************************
//
// 向总线写数据
//
******************************************************************************************/
void IICSendByte(unsigned char ch)
{
      unsigned char i; 
    for(i = 8;i >0;i--) 
    { 
      if((ch&0x80)!=0) 
            I2CPORT |= SDA; //Set the data bit value 
      else 
            I2CPORT &= ~SDA; 
      I2CSetupDelay(); 
      I2CPORT |= SCL; 
      I2CBitDelay(); 
      I2CPORT &= ~SCL; 
      ch <<= 1; 
    } 
    I2CPORT |= SDA; 
    I2CDIR &= ~SDA; //Set SDA as input I2CSetupDelay(); 
    I2CPORT |= SCL; //Clock the line to get ACK 
    I2CBitDelay();
// 
    if((I2CPORT & SDA)==0) { 
    //Look for ACK from slave device 
        I2CPORT &= ~SCL; //Restore clock line 
        I2CDIR |= SDA; //SDA back as output 
    } 
    else 
    { 
    //No acknowledgment received from slave device 
    //Some error action can be performed here 
    //For now, just restore the bus 
        I2CPORT &= ~SCL; 
        I2CDIR |= SDA; 
    }

}
/******************************************************************************************
//
// 总线上读数据
//
******************************************************************************************/
unsigned char IICReceiveByte(void)
{
    unsigned char i,ch=0; 
    I2CDIR &= ~SDA; 
    //Set the SDA as input 
    for(i = 8;i > 0;i--) 
    { 
    ch <<= 1; 
    I2CSetupDelay(); 
    //Wait a bit 
    I2CPORT |= SCL; //Clock it in 
    I2CSetupDelay(); //Wait a bit 
    if((I2CPORT & SDA)!=0) ch++; 
    I2CPORT &= ~SCL; //Restore clock to low state 
    I2CBitDelay(); 
    }// 
    I2CPORT &= ~SDA; 
    //SDA set low 
    I2CDIR |= SDA; 
    //Set SDA as output 
    I2CSetupDelay(); 
    I2CPORT |= SCL; //Clock the line to give    ACK 
    I2CBitDelay();// 
    I2CPORT &= ~SCL; 
    return ch; 

}

/******************************************************************************************
//
******************************************************************************************/
void WriteIicFunc(unsigned char *DataBuff,uchar ByteQuantity,uint Address) {
  
        unsigned char j;
        IICStart();
  		  IICSendByte(0xA0);

  		  delayXms(10);
  		  IICSendByte((unsigned char)(Address>>8));     //0x03
  		  delayXms(10);
  		  IICSendByte((unsigned char)Address);
  		  delayXms(10);
  		  j=ByteQuantity;
  		  while(j--)
      		{
      			IICSendByte(*DataBuff++);

  		  }
        IICStop();
        delayXms(200);
}


/******************************************************************************************
//
******************************************************************************************/
void ReadIicFunc(unsigned char *DataBuff,uchar ByteQuantity,uint Address) {           
        
        IICStart();
  		  IICSendByte(0xA0);
  		  delayXms(10);
  		  IICSendByte((unsigned char)(Address>>8));     //0x03
  		  delayXms(10);
  		  IICSendByte((unsigned char)Address);

      	IICStart();
    		IICSendByte(0XA1);
    		delayXms(10);
    	while(--ByteQuantity)
      		{
      			*DataBuff++=IICReceiveByte();

      		}
	      IICStop();
}

float read_IIC_float(uint adr)
{  
	ReadIicFunc((unsigned char *)&IIC_union.f,4,adr);
	return IIC_union.f;	
}