I2c Overview < Web Exclusive >

The slave device with the matching address responds with an Acknowledge (ACK) bit (low), signaling it is ready, or a Not Acknowledge (NACK) bit (high).

Multiple masters can control the same slave, and multiple slaves can reside on the same bus. I2C Overview

I2C (Inter-Integrated Circuit), often pronounced "eye-squared-see" or "eye-two-see," is a popular, synchronous, multi-master/multi-slave communication protocol invented in 1982 by Philips Semiconductors (now NXP). It is used for short-distance, intra-board communication between a processor and low-speed peripherals such as sensors, LCDs, and memory chips. Its hallmark is using only two wires for communication, making it highly efficient for managing multiple devices on a single bus. The slave device with the matching address responds

Uses a Serial Data Line ( SDA ) and a Serial Clock Line ( SCL ). The master releases the SDA line to high

The master releases the SDA line to high while SCL is high, signaling the end of transmission. Advantages and Limitations Understanding I2C