i2c_sd2405.c

mega16 twi与sd2405接口程序 iar avr 4.20 调试通过

/*****************************************************

Chip type           : ATmega16
Program type        : Application
Clock frequency     : 12.000000 MHz
*****************************************************/

#include <iom16.h>  
#include <inavr.h> 
#include <iomacro.h>
#include <intrinsics.h>
#include <math.h>   
#define uchar unsigned char
#define uint  unsigned int 
#define STR  PORTB_Bit0
#define CLK  PORTB_Bit1
#define DI   PORTB_Bit2
#define TW_START            0x08        // Master 
#define TW_REP_START        0x10 
#define TW_MT_SLA_ACK       0x18        // Master Transmitter  
#define TW_MT_SLA_NACK      0x20 
#define TW_MT_DATA_ACK      0x28 
#define TW_MT_DATA_NACK     0x30 
#define TW_MT_ARB_LOST      0x38 
#define TW_MR_ARB_LOST      0x38        // Master Receiver 
#define TW_MR_SLA_ACK       0x40 
#define TW_MR_SLA_NACK      0x48 
#define TW_MR_DATA_ACK      0x50 
#define TW_MR_DATA_NACK     0x58 
//*************I2C************************
#define SD2405_ADDRESS 0x64

uchar date[7];
   


//*************************************




//***************I2C**********************
void I2C_init(void)
{
    TWSR=0x00;    // 2 Wire Bus initialization
    TWBR=0x04;    // Generate Acknowledge Pulse:On
    TWAR=0x00;    // 2 Wire Bus Slave Address:0h
    TWCR=0x44;    // General Call Recognition:Off,Bit Rate: 250.000 kHz
}
/*void I2C_init(void)
{
    SCL_Output = 0;
    SDA_Output = 0;
    SCL_Low;
    SDA_Low;
}*/

//产生启动信号
unsigned char I2C_start(void)               //产生启动信号
{
  TWCR = (1<<TWINT)|(1<<TWSTA)|(1<<TWEN);
  while (!(TWCR & (1<<TWINT))){};
  return 1;
}

//产生停止信号
void I2C_stop(void)                         //产生停止信号
{
  TWCR = (1<<TWINT)|(1<<TWEN)|(1<<TWSTO);
}

//向总线写一字节,并返回有无应答
unsigned char I2C_write(unsigned char c)    //向总线写一字节,并返回有无应答
{
    unsigned char ack=1;
    TWDR = c;
    TWCR = (1<<TWINT)|(1<<TWEN);
    while (!(TWCR & (1<<TWINT))){};
    if((TWSR & 0xF8) != TW_MT_SLA_ACK)
        ack = 0;
    return ack;  
}


//读一字节 ack: 1时应答，0时不应答
unsigned char I2C_read(unsigned char ack)   //读一字节 ack: 1时应答，0时不应答
{
    if (ack)
        TWCR = (1<<TWINT)|(1<<TWEN)|(1<<TWEA);    
    else
        TWCR = (1<<TWINT)|(1<<TWEN);
    while (!(TWCR & (1<<TWINT))){};    
    return(TWDR);  
}


/******写SD2400允许程序******/

void WriteTimeOn(void)
{		
	I2C_start();
	I2C_write(SD2405_ADDRESS);// 发写从机写寻址字节 //I2CSendByte(0x64);      
	                             //I2CWaitAck();   
        I2C_write(0x10);        // I2CSendByte(0x10);//设置写地址10H      
	                         //I2CWaitAck();	
	I2C_write(0x80);	//I2CSendByte(0x80);//置WRTC1=1      
	                        //I2CWaitAck();
	I2C_stop(); 
	
	I2C_start();
	I2C_write(SD2405_ADDRESS);        //I2CSendByte(0x64);      
	                                  //I2CWaitAck();   
        I2C_write(0x0f);                   //I2CSendByte(0x0F);//设置写地址0FH      
	                                  // I2CWaitAck();	
	I2C_write(0x84);                  //I2CSendByte(0x84);//置WRTC2,WRTC3=1      
	                                  //I2CWaitAck();
	I2C_stop(); 
	
}
/******写SD2400禁止程序******/
void WriteTimeOff(void)
{		
	
	I2C_start();
	I2C_write(SD2405_ADDRESS);        //I2CSendByte(0x64);      
	                                 //I2CWaitAck();   
        I2C_write(0x0f);               // I2CSendByte(0x0F);//设置写地址0FH      
	                               //I2CWaitAck();	
	I2C_write(0x0);          //I2CSendByte(0x0) ;//置WRTC2,WRTC3=0      
	                        //I2CWaitAck();

	I2C_write(0x0);              //I2CSendByte(0x0) ;//置WRTC1=0(10H地址)      
	                           //I2CWaitAck();
	I2C_stop(); 
}
/******写SD2400实时数据寄存器******/
void SD2405_write(unsigned char Addr,unsigned char n, unsigned char* arr)
{
    unsigned char i;
     WriteTimeOn();
    I2C_start();					// 发起始信号
    I2C_write(SD2405_ADDRESS);	// 发写从机写寻址字节
    //I2C_write(Addr>>8);				// 发存储单元地址高字节
    I2C_write(Addr);				// 发存储单元地址低字节
    for (i=1;i<=n;i++)
    {
        I2C_write(*arr);			// 写一个字节数据到24C256
        arr++;
    } 
    I2C_stop();		  
    I2C_start();
    I2C_write(SD2405_ADDRESS);//I2CSendByte(0x64);      
	                          //I2CWaitAck();   
        I2C_write(0x12);        // I2CSendByte(0x12);//设置写起始地址      
	                        //I2CWaitAck();		
        I2C_write(0x00);      //I2CSendByte(0x00);//清零数字调整寄存器      
	                      //I2CWaitAck();        
	I2C_stop();  
	
	WriteTimeOff();        
    
     
}


//*****************************************
 void SD2405_inrupt(void)
 {
    WriteTimeOn(); 
    I2C_start();
    I2C_write(SD2405_ADDRESS);	
    //I2C_write(0x0e);	// address=0x0e
   // I2C_write(0x01);
    //I2C_write(0x84);   //address=0x0f
    I2C_write(0x10);
    I2C_write(0xa1);  //address=0x10;
    I2C_write(0xbf); //address=0x11
    I2C_stop();
   // I2C_write(SD2405_ADDRESS);
    //I2C_write(0x07);
  //  I2C_write(0x01); //address=0x07
    WriteTimeOff();   
 }


//************************************
void SD2405_read(unsigned char Addr,unsigned char n, unsigned char* arr)
{
    unsigned char i;
    I2C_start();						// 发起始信号
    I2C_write(SD2405_ADDRESS);		// 发写从机写寻址字节
   // I2C_write(Addr>>8); 				// 发存储单元地址高字节
    I2C_write(Addr);					// 发存储单元地址低字节
    I2C_start();   						// 发起始信号
    I2C_write(SD2405_ADDRESS | 1);	// 发从机读寻址字节    
    for (i=1;i<=n-1;i++)
    {
        *arr = I2C_read(1);			// 读一个字节数据，返回ACK   
        arr++;
    }
    *arr=I2C_read(0);				// 读最后一个字节数据，返回NO ACK
    I2C_stop();						// 发停止信号
}



//**************************************
void main(void)
{
 date[0]=0x0;
 date[1]=0x30;
 date[2]=0x91;
 date[3]=0x02;
 date[4]=0x16;
 date[5]=0x012;
 date[6]=0x08;
 SD2405_write(0x0,7, date);
 
  while (1)
  {
       
        SD2405_read(0,7,date);
         __delay_cycles(450000); //delay time  
         
  }
      
    
}