SLVA704 June   2015 INA209 , INA219 , INA220 , INA220-Q1 , INA223 , INA226 , INA226-Q1 , INA228 , INA228-Q1 , INA230 , INA231 , INA233 , INA234 , INA237 , INA237-Q1 , INA238 , INA238-Q1 , INA3221 , INA3221-Q1 , LM8323 , LM8325-1 , LM8327 , LM8328 , LM8330 , LM8333 , LM8335 , OPT3001 , OPT3004 , P82B715 , P82B96 , PCA9306 , PCA9306-Q1 , PCA9515A , PCA9515B , PCA9518 , PCA9534 , PCA9534A , PCA9535 , PCA9536 , PCA9538 , PCA9539 , PCA9543A , PCA9544A , PCA9545A , PCA9546A , PCA9548A , PCA9554 , PCA9554A , PCA9555 , PCA9557 , PCF8574 , PCF8574A , PCF8575 , PCF8575C , TCA4311A , TCA5405 , TCA6408A , TCA6416A , TCA6418E , TCA6424A , TCA6507 , TCA8418 , TCA8418E , TCA8424 , TCA9406 , TCA9509 , TCA9517 , TCA9517A , TCA9534 , TCA9534A , TCA9535 , TCA9538 , TCA9539 , TCA9539-Q1 , TCA9543A , TCA9544A , TCA9545A , TCA9546A , TCA9548A , TCA9554 , TCA9554A , TCA9555 , TCA9617A , TCA9617B , TCA9800 , TCA9801 , TCA9802 , TCA9803

 

  1.   Understanding the I2C Bus
    1.     Trademarks
    2. 1 Electrical Characteristics
      1. 1.1 Open-Drain for Bidirectional Communication
        1. 1.1.1 Open-Drain Pulling Low
        2. 1.1.2 Open-Drain Releasing Bus
    3. 2 I2C Interface
      1. 2.1 General I2C Operation
        1. 2.1.1 START and STOP Conditions
        2. 2.1.2 Repeated START Condition
      2. 2.2 Data Validity and Byte Format
      3. 2.3 Acknowledge (ACK) and Not Acknowledge (NACK)
    4. 3 I2C Data
      1. 3.1 Writing to a Slave On The I2C Bus
      2. 3.2 Reading From a Slave On The I2C Bus

2.2 Data Validity and Byte Format

One data bit is transferred during each clock pulse of the SCL. One byte is comprised of eight bits on the SDA line. A byte may either be a device address, register address, or data written to or read from a slave. Data is transferred Most Significant Bit (MSB) first. Any number of data bytes can be transferred from the master to slave between the START and STOP conditions. Data on the SDA line must remain stable during the high phase of the clock period, as changes in the data line when the SCL is high are interpreted as control commands (START or STOP).

I2C_Data_Byte.gifFigure 6. Example of Single Byte Data Transfer