Each device connected to an I2C Bus is recognized by a unique address. Each device can operate as either a transmitter or a receiver, depending on the function of the device. A device connected to the I2C Bus can also be considered as the master or the slave when performing data transfers. A master device is the device that initiates a data transfer on the bus and generates the clock signals to permit that transfer. During this transfer, any device addressed by this master is considered a slave. The I2C module supports the multi-master mode, in which one or more devices capable of controlling an I2C Bus can be connected to the same I2C Bus.
For data communication, the I2C module has a serial data pin (SDA) and a serial clock pin (SCL). These two pins carry information between the C28x device and other devices connected to the I2C Bus. The SDA and SCL pins both are bidirectional. They each must be connected to a positive supply voltage using a pullup resistor. When the bus is free, both pins are high. The driver of these two pins has an open-drain configuration to perform the required wired-AND function. There are two major transfer techniques:
The I2C module consists of the following primary blocks: