i2c_demo.c.bak

本人改编和测试过的用于AVR mega128关于I2C总线的应用实例--使用EEPROM的读写方法。采用ICCAVR编译器实验。

// ***************   I2C driver Demo V 1.0   *************
// 通用性的 IO模拟方式的I2C接口操作
// 最大400KCLK@1.8V
// *******************************************************

#include <iom1281v.h>
#include <MACROS.h>

#include <DC_Defines.h>

#include "I2C.h"



void EEPROM_Write(unsigned char, unsigned int, unsigned char);
unsigned char EEPROM_Read(unsigned char, unsigned int);


// **************************************************************** //
// ***                     Init_I2C();							*** //
// *** This routine will setup the I2C port direction registers *** //
// **************************************************************** //

// ***************************************************************** //
// ***                     I2C_Start();	 		  		 	   	 *** //
// *** This routine will set the I2C start condition on the bus, *** //
// *** All commands must be preceded by a START condition 		 *** //
// ***************************************************************** //

// ***************************************************************** //
// ***                     I2C_Stop();	 		  		 	   	 *** //
// *** This routine will set the I2C stop condition on the bus,  *** //
// *** All commands must end with a STOP condition 		         *** //
// ***************************************************************** //

// *********************************************************************** //
// ***                Write_I2C_Control(0x0A,0,0);	  		  	       *** //
// *** This routine will write the I2C device code, the device address *** //
// *** setup on the hardware pins A0,A1 & A2, and also the W/R bit     *** //
// *** So for an external EEPROM, such as the 24LC04B you would need   *** //
// *** a device code of 1010 (0x0A),   	  	  		  	  			   *** //
// *** hardware address 0 (if pins A0,A1 & A2 are left unconnected,    *** //
// *** and the last parameter is R/W. Write is active low			   *** //
// *********************************************************************** //

// *********************************************************************** //
// ***                          I2C_Ackn();							   *** //
// *** This routine will clock the ACK bit from the I2C slave device   *** //
// *** it will return TRUE for a fail, and FALSE for a correct ACK bit *** //
// *********************************************************************** //

// ************************************************************** //
// ***                     Write_I2C_Byte();				  *** //
// *** This routine will clock a byte to the slave I2C device *** //
// ************************************************************** //

// ************************************************************************** //
// ***                       Read_I2C_Byte();					          *** //
// *** This routine will read and return a byte from the I2C slave device *** //
// ************************************************************************** //



// *********************************************************************** //
// ***                 Example of using Imagecraft I2C driver          *** //
// ***              to write to an external 8 bit address EEPROM       *** //
// *** H_ADD is the hardware address set on the device A0,A1 & A2 pins *** //
// *** M_ADD is the devices internal memory address                    *** //
// *** Data is user data to be writen 								   *** //
// *********************************************************************** //

void EEPROM_Write(unsigned char H_ADD, unsigned int M_ADD, unsigned char Data)
{
 I2C_Start();			   			   // Set I2C start condition

 Write_I2C_Control(0x0A,H_ADD,0);	   // Send the EEPROM control Byte

 Write_I2C_Byte(M_ADD>>8);				   // Send the EEPROM internal Address higher byte.
 
 Write_I2C_Byte(M_ADD);            // Send the EEPROM internal Address lower byte.
 
 Write_I2C_Byte(Data);				   // Send the EEPROM Data
 
 I2C_Stop();	  					   // Set I2C Stop condition
}



// *********************************************************************** //
// ***              Example of using Imagecraft I2C driver             *** //
// ***            to Read an external 8 bit address EEPROM             *** //
// *** H_ADD is the hardware address set on the device A0,A1 & A2 pins *** //
// *** M_ADD is the devices internal memory address                    *** //
// *** Data is user data to be writen 								   *** //
// *********************************************************************** //

unsigned char EEPROM_Read(unsigned char H_ADD, unsigned int M_ADD)
{
 unsigned char Temp;			   		// Temp RAM for EEPROM Read
 
 I2C_Start();			   			   // Set I2C start condition

 Write_I2C_Control(0x0A,H_ADD,0);	   // Send the EEPROM control Byte
 									   // Dummy write to set address

 Write_I2C_Byte(M_ADD>>8);				// Send the EEPROM internal Address Higher byte.
 Write_I2C_Byte(M_ADD);     // Send the EEPROM internal Address lower byte.
 
 I2C_Start();			   			   // Set I2C start condition
 
 Write_I2C_Control(0x0A,H_ADD,1);	   // Send the EEPROM control Byte
 
 Temp = Read_I2C_Byte();			   // Read data from EEPROM
 
 I2C_Stop();	  					   // Set I2C Stop condition

 return Temp;						   // Return data from EEPROM
}




//AT24C512B使用2BYTE片内地址。
unsigned char bf[26];
void main (void)
{
  unsigned int i;
  unsigned char j, k;
  unsigned int c;			  // Temp Ram used for write delay
  volatile unsigned char data;
  
  DDRG |=BIT(PG1)|BIT(PG0);
  PORTG |=BIT(PG1)|BIT(PG0); //VCC =high. Pull up=1.
  
  I2C_DIR |= BIT(PD0)|BIT(PD1);  	 			  // Set Port B to Outputs
  
  Init_I2C();	   			  // Setup the hardware port
  
  while (true)
  {
    for (k=0,i=0x1050, j='A'; 1; i++,j++ )
    {
    	EEPROM_Write( 1 , i , j );
    	
    	for(c=0;c<5000;c++);		  // Delay for EEPROM Write
    	
    	data = EEPROM_Read( 1, i );	  // Read device 1, memory address 1
    	bf[k++] =data;
    	if (j=='Z') break;
    	
    }
    
    for(c=0;c<5000;c++);		  // Delay for EEPROM Write
  }

}