The LDC1312/4 use I2C for register access with a maximum speed of 400 kbit/s. The device registers are 16 bits wide, and so a repeated start is used to access the 2nd byte of data. This sequence follows the standard I2C 7bit slave address followed by an 8 bit pointer register byte to set the register address. Refer to Figure 11 and Figure 12 for proper protocol diagrams. The device does not use I2C clock stretching.
When the ADDR pin is set low, the device I2C address is 0x2A; when the ADDR pin is set high, the I2C address is 0x2B. The ADDR pin setting can be changed while the device is in Shutdown Mode to select the alternate I2C address.