Why is a Nack sent after the last byte?

Why is a Nack sent after the last byte?

A MASTER will also send a NACK after the last byte of the transmission it wants to read from a SLAVE to indicate that the SLAVE should stop transmission. Figure 6 shows a MASTER-transmitter addressing and writing data to a SLAVE-receiver with a 7-bit address.

How do you read I2C?

A basic Master to slave read or write sequence for I2C follows the following order:

  1. Send the START bit (S).
  2. Send the slave address (ADDR).
  3. Send the Read(R)-1 / Write(W)-0 bit.
  4. Wait for/Send an acknowledge bit (A).
  5. Send/Receive the data byte (8 bits) (DATA).
  6. Expect/Send acknowledge bit (A).
  7. Send the STOP bit (P).

What is the difference between ACK and NACK?

If you use ACK, the sender will stop sending and keep its backlog until the link is restored. If you use NACK instead, then the receiver may eventually tell you that it has not received the packet that fell off the sender’s backlog since a long time, and the connection is essentially unrecoverable.

Where do we use I2C communication?

The I2C bus protocol is most commonly used in master and slave communication wherein the master is called “microcontroller”, and the slave is called other devices such as ADC, EEPROM, DAC and similar devices in the embedded system.

What is ACK and NACK message?

An Acknowledgement (ACK) or Negative Acknowledgement (NACK) is a short message sent by the receiver to the transmitter to indicate whether it has correctly or incorrectly received a data packet, respectively.

What does ACK stand for?


Acronym Definition
ACK Acknowledge/Acknowledgement/Acknowledged
ACK Amar Chitra Katha (Indian entertainment company)
ACK Akademickie Centrum Kultury (Polish: Academic Center for Culture; Lublin, Poland)
ACK Arbeitsgemeinschaft Christlicher Kirchen (German: Council of Christian Churches)