AVR Freaks

Hello,

I want to interface 24LC1025 with atmega32. 24LC1025 is divided in two block of 512kb and in control frame there is a bit block select bit to select the block. I can read and write first block without any problem(random read and write).

But when I try to read second block I getting 255. I am sure my I2C rutains are correct because as I say, I can read and write on first block. This is my code. Please help to solve the problem.

//Microcontroller- atmega32

//Compiler-WINAVR 20100110 ,AVR STDIO 7

//CRESTAL- FREQ-11.0592Mhz

void main(void)

{

 unsigned char log_data[5];

        EEPROM_WriteByte_1Mb(100,10,0);    //work fine
        EEPROM_WriteByte_1Mb(200,20,0);    //work fine
        EEPROM_WriteByte_1Mb(300,30,1);    //not working
        EEPROM_WriteByte_1Mb(400,40,1);    //not working

while(1){

             log_data[0]= EEPROM_ReadByte_1Mb(100,0);     //Read block 0, this by setting block select bit =0,this is working fine
             log_data[1]= EEPROM_ReadByte_1Mb(200,0);
             log_data[2]= EEPROM_ReadByte_1Mb(300,1);     //Read block  1, this by setting block select bit =1,this not work
             log_data[3]= EEPROM_ReadByte_1Mb(400,1);

ms(100);

}

}

unsigned char check_frame;     //This is for checking value of control frame, When I select block 0, here value is A0, this working fine

                                              //when I select block 1, here value is A8, this not working.

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

Input- address,data,block bit

output- non

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

void EEPROM_WriteByte_1Mb(unsigned int eeprom_Address, unsigned char eeprom_Data, unsigned char block)
{
    unsigned char address_wh,address_wl;
    unsigned char Page_Number=0x00;

       if(block==0){
       Page_Number=0x00;                             //select first block ,first 512Kb
       }
       else if(block==1){
       Page_Number=0x04;                             //select second block ,second 512Kb
       }
       else{
       Page_Number=0x00;                           //Default select block 1
       }

    address_wh= ((eeprom_Address>>8) & 0x00FF);                     //break int to char
    address_wl= (eeprom_Address & 0X00FF);

    I2C_Start();                                                                           // Start i2c communication

    I2C_Write(EEPROM_ID|(Page_Number<<1));                          // connect to 24LC1025 and above by sending its ID on I2c Bus
    check_frame=(EEPROM_ID|(Page_Number<<1));
    I2C_Ack();

    I2C_Write(address_wh);                      //Send address high
    I2C_Ack();

    I2C_Write(address_wl);                       //Send address low
    I2C_Ack();

    I2C_Write(eeprom_Data);                  // Write the data at specified address
    I2C_Ack();
    I2C_Stop();                                     // Stop i2c communication after Writing the data

    ms(5);                                            //Should be 5 ms delay in every random write

    return;

}

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

Input- address and block bit

output- unsigned char data

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

unsigned char EEPROM_ReadByte_1Mb(unsigned int eeprom_Address,unsigned char block)
{
    unsigned char eeprom_Data;  //,address_h,address_l;
    unsigned char address_rh,address_rl;
    unsigned char Page_Number=0x00;

    if(block==0){
    Page_Number=0x00;                             //select first block ,first 512Kb
    }
    else if(block==1){
    Page_Number=0x04;                             //select second block ,second 512Kb
    }
    else{
    Page_Number=0x00;                           //Default select block 1
    }

    address_rh= ((eeprom_Address>>8) & 0x00FF); //break int to char
    address_rl= (eeprom_Address & 0X00FF);

    I2C_Start();                                                      // Start i2c communication
    I2C_Write(EEPROM_ID|(Page_Number<<1));      // connect to AT24LC1025 and above(write) by sending its ID on I2c Bus
    I2C_Ack();

    I2C_Write(address_rh);                       // address high
    I2C_Ack();
    I2C_Write(address_rl);                       // address low
    I2C_Ack();

    I2C_Start();                                                  // Start i2c communication
    I2C_Write(0xA1|(Page_Number<<1));           // connect to 24lc1025(read) by sending its ID on I2c Bus
    I2C_Ack();

    eeprom_Data = I2C_Read();                   // Read the data from specified address
    I2C_NoAck();
    I2C_Stop();                                           // Stop i2c communication after Reading the data

      us(10);
    return (eeprom_Data);                        // Return the Read data
}