SNLA267A March 2019 – June 2019 DS90UB953-Q1 , DS90UB954-Q1 , DS90UB960-Q1
The I2C-compatible interface for each device consists of the clock (SCL) and data (SDA) pins. These two signals have open-drain I/Os. Both signals must be pulled up to VDD by an external resistor. A logic zero is transmitted by driving the output low. A logic one is transmitted by releasing the output and allowing it to be pulled up externally. The appropriate pullup resistor values will depend upon the total bus capacitance and operating speed.
Each serializer or deserializer determines its I2C slave address from a resistor termination circuit attached to the IDX pin. This value is loaded into the I2C Device ID register at address 0x00. See the device data sheets for IDX configuration requirements and available I2C addresses for each device.