Re: Writing data to serial EEPROM

The device is 24FC512 serial EEPROM.

I tried to write two datas at different location but couldnt write.

But if my address is 0x0000 and write two datas continously i can write and read.

I am not sure y it cant write at different locations.

The device is 24FC512 serial EEPROM.

I tried to write two datas at different location but couldnt write.

But if my address is 0x0000 and write two datas continously i can write and read.

I am not sure y it cant write at different locations.

Hard to say without seeing your code.

Non-sequential addresses, each with a separate write transaction. Each transaction fully setting the device's internal address with write commencing after the stop condition starting a self-timed write, the completion of which you must either ACK-poll or implement a fixed worst-case delay.

My coding is,

#define EEPROM_WR  0xA2
#define EEPROM_RD  0xA3

sbit SCLK = P1^1;
sbit SDA  = P1^2;

unsigned int ptr;

typedef union {
                float   f;
                char   b[4];
             }   fval;

void EEPROM_Location(unsigned int x)
  {
     ptr = x;
  }

void EEPROM_WrByte(unsigned char x)
  {
     I2C_Start();       //START I2C PROTOCOL
     I2C_Write(EEPROM_WR);      //CTRL WORD FOR WRITE MODE
     I2C_Write((char)(ptr>>8)); //HIGH ADDRESS BYTE
     I2C_Write((char)ptr);     //LOW ADDRESS BYTE
     I2C_Write(x);               //WRITE THE DATA
     I2C_Stop();
     ptr++;
     LongDelay(15);
     return;
  }

void EEPROM_WrInt(unsigned int x)
  {
     I2C_Start();       //START THE I2C PROTOCOL
     I2C_Write(EEPROM_WR); //CTRL WORD FOR WRITE MODE
     I2C_Write((char)(ptr>>8)); //HIGH ADDRESS BYTE
     I2C_Write((char)ptr);      // LOW ADDRESS BYTE
     I2C_Write((char)(x>>8));  //HIGH DATA BYTE
     I2C_Write((char)(x));         // LOW DATA BYTE
     I2C_Stop();

     ptr+=2;
     LongDelay(15);
     return;
  }

This routine is called as "eeprom.c" The main function code is,

extern unsigned int ptr;

void main(void)
  {
     unsigned char a,b,c;
     unsigned char x,y,z;

     a = 0x32;
     b = 0x45;
     c = 0x56;

     ptr = 0x0000;

     EEPROM_Location(ptr);
     EEPROM_WrByte(a);
     LongDelay(15);

     EEPROM_Location(ptr);
     EEPROM_WrByte(b);
     LongDelay(15);

     EEPROM_Location(ptr);
     EEPROM_WrByte(c);
     LongDelay(15);

     ptr = 0x0000;

     EEPROM_Location(ptr);
     x = EEPROM_RdByte();
     LongDelay(15);

     EEPROM_Location(ptr);
     y = EEPROM_RdByte();
     LongDelay(15);

     EEPROM_Location(ptr);
     z = EEPROM_RdByte();
     LongDelay(15);
  }

With ptr = 0x0000, if i print the values x,y,z the output is correct. If i initialize my ptr = 0xF000, and write the data into it and read the data from same location, no output. I dont know where is the problem?

I don't see EEPROM_RdByte().

"... and read the data from same location, no output."

What does "no output" mean?

Thank you.

I had solved the problem.