TUSB216 supports 100 and 400 kHz I2C for device configuration, status read back and test purposes. For detail electrical and functional specifications refer to I2C Bus Specification – STANDARD and FAST MODE. This controller is enabled after SCL and SDA pins are sampled high shortly after return from shutdown. In this mode, the CSR can be accessed by I2C read/write transaction to 7-bit slave address 0x2C. It is advised to set CFG_ACTIVE bit before changing values. This halts the FSM, and reset it after all changes are made. This ensure proper startup into high-speed mode.