I²C Byte Write

Please put this data at this address…

An I2C byte write is used to write a byte of data to a specific address.

i2c-byte-write1.png

EEPROM Byte Write Procedure

  1. Check for bus idle
  2. Send start condition, wait for it to complete
  3. Write control byte (with device address)
  4. Check for bus idle
  5. Write high byte of memory address
  6. Check for bus idle
  7. Write low byte of memory address
  8. Check for bus idle
  9. Write byte of data
  10. Check for bus idle
  11. Send stop condition, wait for it to complete
  12. Wait for write cycle to complete (ACK from EEPROM)

Example Code (PIC18)

Specific I2C function names and parameters may differ depending on your target device, compiler and/or peripheral library.

IdleI2C(); // Ensure module is idle
StartI2C();
while (SSPCON2bits.SEN);
// Initiate START condition
// Wait until START condition is over
WriteI2C(0xA0); // Write 1 byte - R/W bit should be 0
IdleI2C(); // Ensure module is idle
WriteI2C(HighAddress); // Write high address byte to EEPROM
IdleI2C(); // Ensure module is idle
WriteI2C(LowAddress); // Write low address byte to EEPROM
IdleI2C(); // Ensure module is idle
WriteI2C(Data); // Write data byte to EEPROM
IdleI2C(); // Ensure module is idle
StopI2C();
while (SSPCON2bits.PEN);
// Send STOP condition
// Wait until STOP condition is over
while (EEAckPolling(0xA0)); // Wait for write cycle to complete
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