isr_i2c.c

基于EEPROM AT24C64的数据存储

#include <./Atmel/at89x52.h>
#include    "source.h"
#define 	SDA_SET() 		(SDA=1)
#define 	SDA_CLR() 		(SDA=0)
//#define 	SDA_VAL()		(PDDR  &0x2)

#define 	SCL_SET() 		(SCL=1)
#define 	SCL_CLR() 		(SCL=0)


I2Cdesc	I2c;	//the device decriptor

extern void I2cFinish(I2Cdesc *I2C_pt);
unsigned int idata I2c_timer_cnt=0;
void Init_I2c_Timer(unsigned int us){//MCLK@18.432MHz
	//(((MCLK/12))*(256-TH0))us
    TH0=TIMER0H;//20us
	TL0=TH0;
	I2c_timer_cnt=us/20;
	TR0=1; // let timer 0 run      // TCON /
}
void Start_I2c_Timer(unsigned int us){
	I2c_timer_cnt=us/20;
	TL0=TH0;
	TR0=1; // let timer 0 run      // TCON /
}
void Stop_I2c_Timer(void){
	TR0=0;
}
unsigned char SDA_VAL(void){
	return SDA;	
}
//*-----------------------------------------------------------------------------
//* 函数名称  : I2CWrite (I2Cdesc *I2C_pt, u_short loadAddress, u_char nbByte)
//* Object    : I2C
//* 输入参数  : <I2C_pt> =   为I2C的描述指针，其结构定义在source.h中
//*			      : loadAddress  为I2C的输入的存储单元的地址
//*			      : nbByte       为要写入I2C的字节数
//* 输出变量  : 无
//* 功能       ：把TxEnd中的数据的nbByte字节写到loadAddress地址
//*-----------------------------------------------------------------------------
void I2CWrite (I2Cdesc *I2C_pt, unsigned int loadAddress, unsigned int nbByte){	
    I2C_pt->state = NOK;
	  I2C_pt->operate=WRITE_BIT;
	  I2C_pt->Error=0;	
									    //* initialize state
    SCL_SET();			  //* set SCL line
    SDA_SET();		    //* set SDA line

    I2C_pt->I2CByte = I2C_pt->deviceAddress | WRITE_BIT ;	    //* get byte to transmit
    I2C_pt->loadAddress = loadAddress;					    //* get address
    I2C_pt->mode = HIGH_ADDRESS_WRITE;					    //* next mode
    I2C_pt->nbI2CByte = nbByte;							    //* get number of byte to transmit
    I2C_pt->countBit = 8;								    //* initialize countBit
    I2C_pt->nb_ACK = 10;								    //* initialize nb_ACK
    //* change interrupt handler to I2CTxSendStartSDA
    I2C_pt->I2CTCHandler = I2CTxSendStartSDA;
    //* Enable RC compare interrupt
    Start_I2c_Timer(I2C_pt->Timer_Gap_us);//start Timer
}
//*-----------------------------------------------------------------------------
//* 函数名称       : I2CRead (I2Cdesc *I2C_pt, u_short loadAddress, u_char nbByte)
//* Object         : I2C
//* 输入参数       : <I2C_pt> =  为I2C的描述指针，其结构定义在source.h中
//*			           : loadAddress 为I2C的输入的存储单元的地址
//*			           : nbByte      为要写入I2C的字节数
//* 输出变量       : 无
//* 功能           ：从loadAddress地址中读nbByted放到RxEnd中
//*-----------------------------------------------------------------------------
void I2CRead (I2Cdesc *I2C_pt, unsigned int loadAddress, unsigned int nbByte){

    I2C_pt->state = NOK;            //* initialize state
	  I2C_pt->operate=READ_BIT;
	  I2C_pt->Error=0;

    SCL_SET();			//* set SCL line
    SDA_SET();		  //* set SDA line

    I2C_pt->I2CByte = I2C_pt->deviceAddress | WRITE_BIT ;     //* get byte to read
    I2C_pt->loadAddress = loadAddress;                  //* get address
    I2C_pt->mode = HIGH_ADDRESS_READ;               //* next mode
    I2C_pt->nbI2CByte = nbByte;         //* get nb byte to transmit

    I2C_pt->countBit = 8;       //* initialize countBit
    I2C_pt->nb_ACK = 10;        //* initialize nb_ACK
    //* change interrupt handler to I2CTxSendStartSDA 
    I2C_pt->I2CTCHandler = I2CTxSendStartSDA;
    //* Enable RC compare interrupt
	 Start_I2c_Timer(I2C_pt->Timer_Gap_us);//start Timer
}

//*-----------------------------------------------------------------------------
//* 函数名称       : I2CDeviceRead (I2Cdesc *I2C_pt)
//* Object         : I2C
//* 输入参数       : <I2C_pt> =  为I2C的描述指针，其结构定义在source.h中
//* 输出变量       : 无
//* 功能           ：为在读字节操作时通知I2C设备，以下的操作为读操作
//*-----------------------------------------------------------------------------
void I2CDeviceRead (I2Cdesc *I2C_pt){
    SDA_SET();     //* set SDA line
    SCL_SET();      //* set SCL line
    
    I2C_pt->I2CByte = I2C_pt->deviceAddress | READ_BIT;      //* get byte to transmit
    I2C_pt->mode = DATA_READ;   //* next mode
    I2C_pt->countBit = 8;       //* initialize countBit
    I2C_pt->nb_ACK = 10;           //* initialize nb_ACK
    //* change interrupt handler to I2CTxSendStartSDA
    I2C_pt->I2CTCHandler = I2CTxSendStartSDA;
}

//*-----------------------------------------------------------------------------
//* 函数名称       : I2CDeviceRead (I2Cdesc *I2C_pt)
//* Object         : I2C
//* 输入参数       : <I2C_pt> =  为I2C的描述指针，其结构定义在source.h中
//* 输出变量       : 无
//* 功能           ：为在写字节操作时通知I2C设备，以下的操作为写操作
//*-----------------------------------------------------------------------------
void I2CDeviceWrite (I2Cdesc *I2C_pt){
    SDA_SET();;     //* set SDA line
    SCL_SET();;        //* set SCL line

    I2C_pt->I2CByte = I2C_pt->deviceAddress | WRITE_BIT;      //* get byte to transmit
    I2C_pt->mode = DATA;   		//* next mode
    I2C_pt->countBit = 8;       //* initialize countBit
    I2C_pt->nb_ACK = 10;           //* initialize nb_ACK
    //* change interrupt handler to I2CTxSendStartSDA
    I2C_pt->I2CTCHandler = I2CTxSendStartSDA;
}
//*-----------------------------------------------------------------------------
//* 函数名称       : I2CTxSendByte (I2Cdesc *I2C_pt)
//* Object         : I2C
//* 输入参数       : <I2C_pt> =  为I2C的描述指针，其结构定义在source.h中
//* 输出变量       : 无
//* 功能           ：为把状态字节，数据，地址等字节写到I2C设备中
//*-----------------------------------------------------------------------------
void I2CTxSendByte (I2Cdesc *I2C_pt){

    SDA_SET();;        //* set SDA line
    switch(I2C_pt->mode){           //* get byte to transmit
	    case DATA :     //Writing data byte now...
	        I2C_pt->I2CByte = *(I2C_pt->TxEnd++);
    	    I2C_pt->nbI2CByte--;
	        if(I2C_pt->nbI2CByte == 0)
                I2C_pt->mode = STOP;               //* next mode
    	    break;
    	case HIGH_ADDRESS_WRITE :   //Write high byte of address (Write operation)...
	        I2C_pt->I2CByte = (unsigned char)(I2C_pt->loadAddress >> 8);
            I2C_pt->mode    = LOW_ADDRESS_WRITE;   //* next mode
	        break;
	    case LOW_ADDRESS_WRITE :    //Write low byte of address (Write operation)...
	        I2C_pt->I2CByte = (unsigned char) I2C_pt->loadAddress;
	        I2C_pt->mode    = DATA;                //* next mode
	        break;
	    case HIGH_ADDRESS_READ :    //Write high byte of address (Read operation)... 
	        I2C_pt->I2CByte = (unsigned char) (I2C_pt->loadAddress >> 8);
            I2C_pt->mode    = LOW_ADDRESS_READ;    //* next mode
	        break;
	    case LOW_ADDRESS_READ :     //Write low byte of address (Read operation)...
	        I2C_pt->I2CByte = (unsigned char) I2C_pt->loadAddress;
	        I2C_pt->mode    = DEVICE_READ;         //* next mode
	        break;
    }
    I2C_pt->countBit = 8;         //* initialize countBit
    I2C_pt->nb_ACK   = 10;        //* initialize nb_ACK
    //* change interrupt handler to I2CTxSendBit
    I2C_pt->I2CTCHandler = I2CTxSendBit;
}


//*-----------------------------------------------------------------------------
//* 函数名称       : I2CTxSendBit (I2Cdesc *I2C_pt)
//* Object         : I2C
//* 输入参数       : <I2C_pt> =  为I2C的描述指针，其结构定义在source.h中
//* 输出变量       : 无
//* 功能           ：根据发送数据的BIT位来判断要发送什么数据在SDA线上
//*-----------------------------------------------------------------------------
void I2CTxSendBit (I2Cdesc *I2C_pt){
    unsigned char bit_val;
    SCL_CLR();		    //* Clear SCL line
    I2C_pt->countBit--;									    //* decrement countBit
    if(I2C_pt->countBit >= 0){				    //* if bit counter = 0 ...
		bit_val = (I2C_pt->I2CByte >> I2C_pt->countBit) & 1;	//* get bit to transfert
		//* Send 0 or 1
		if (bit_val){
   	    SDA_SET();		//* Set SDA line
		}
   else{
		    SDA_CLR();	    //* Clear SDA line
		}
 		//* change interrupt handler to I2CTxSetSCL
		I2C_pt->I2CTCHandler = I2CTxSetSCL;
    }
    else{										//All the bits has been sent...
		//SDA_INPUT();		   	//* set SDA line as an input
		//* change interrupt handler to I2CTxPrepareACK
		I2C_pt->I2CTCHandler = I2CTxPrepareACK;
    }
}
//*-----------------------------------------------------------------------------
//* 函数名称       : I2CTxSendStartSDA (I2Cdesc *I2C_pt)
//* Object         : I2C
//* 输入参数       : <I2C_pt> =  为I2C的描述指针，其结构定义在source.h中
//* 输出变量       : 无
//* 功能           ：为I2C的开始时序SDA的变化
//*-----------------------------------------------------------------------------
void I2CTxSendStartSDA (I2Cdesc *I2C_pt){	
    SDA_CLR();		    //* clear SDA line
    //* change interrupt handler to I2CTxSendStartSCL
    I2C_pt->I2CTCHandler = I2CTxSendStartSCL;
}

//*-----------------------------------------------------------------------------
//* 函数名称       : I2CTxSendStartSDA (I2Cdesc *I2C_pt)
//* Object         : I2C
//* 输入参数       : <I2C_pt> =  为I2C的描述指针，其结构定义在source.h中
//* 输出变量       : 无
//* 功能           ：为I2C的开始时序SCL的变化
//*-----------------------------------------------------------------------------
void I2CTxSendStartSCL (I2Cdesc *I2C_pt){
    SCL_CLR();		    //* clear SCL line
    //* change interrupt handler to I2CTxSendBit
    I2C_pt->I2CTCHandler = I2CTxSendBit;
}

//*-----------------------------------------------------------------------------
//* 函数名称       : I2CTxPrepareSTOP (I2Cdesc *I2C_pt)
//* Object         : I2C
//* 输入参数       : <I2C_pt> =  为I2C的描述指针，其结构定义在source.h中
//* 输出变量       : 无
//* 功能           ：为I2C的发送准备停止
//*-----------------------------------------------------------------------------
void I2CTxPrepareSTOP (I2Cdesc *I2C_pt)
//* Begin
{
    //* clear SDA line
    SDA_CLR();

    //* set SCL line
    SCL_SET();

    //* change interrupt handler to I2CTxSendStopSDA
    I2C_pt->I2CTCHandler = I2CTxSendStopSDA;

//* End
}


//*-----------------------------------------------------------------------------
//* 函数名称       : I2CTxSendStopSCL (I2Cdesc *I2C_pt)
//* Object         : I2C
//* 输入参数       : <I2C_pt> =  为I2C的描述指针，其结构定义在source.h中
//* 输出变量       : 无
//* 功能           ：为I2C的停止时序SCL的变化
//*-----------------------------------------------------------------------------
void I2CTxSendStopSCL (I2Cdesc *I2C_pt){
    SCL_SET();;    //* set SCL line
    //* change interrupt handler to I2CTxSendStopSDA
    I2C_pt->I2CTCHandler = I2CTxSendStopSDA;
}

//*-----------------------------------------------------------------------------
//* 函数名称       : I2CTxSendStopSDA (I2Cdesc *I2C_pt)
//* Object         : I2C
//* 输入参数       : <I2C_pt> =  为I2C的描述指针，其结构定义在source.h中
//* 输出变量       : 无
//* 功能           ：为I2C的停止时序SDA的变化
//*-----------------------------------------------------------------------------
void I2CTxSendStopSDA (I2Cdesc *I2C_pt){
    SDA_SET();;         	//Set SDA line high
    I2C_pt->state = OK;								//Return to "OK"(Idle) state

    I2C_pt->I2CTCHandler = I2C_pt->I2cFinish;		//change interrupt handler
}

//*-----------------------------------------------------------------------------
//* 函数名称       : I2CTxPrepareACK (I2Cdesc *I2C_pt)
//* Object         : I2C
//* 输入参数       : <I2C_pt> =  为I2C的描述指针，其结构定义在source.h中
//* 输出变量       : 无
//* 功能           ：为I2C的发送应答时序的前的准备
//*-----------------------------------------------------------------------------
void I2CTxPrepareACK (I2Cdesc *I2C_pt){
    SCL_SET();		    //* set SCL line
    //* change interrupt handler to I2CTxWaitACK
    I2C_pt->I2CTCHandler = I2CTxWaitACK;
}