The I2C mode supports any slave or master I2C-compatible device. Figure 38-2 shows an example of an I2C bus. Each I2C device is recognized by a unique address and can operate as either a transmitter or a receiver.
A device connected to the I2C bus can be considered as the master or the slave when performing data transfers. A master initiates a data transfer and generates the clock signal SCL. Any device addressed by a master is considered a slave. I2C data is communicated using the serial data (SDA) pin and the serial clock (SCL) pin. Both SDA and SCL are bidirectional and must be connected to a positive supply voltage using a pullup resistor.