Communication to the HDC302x is based upon a command list, which is documented in Table 8-3. Commands other than those documented are undefined and should not be sent to the device. An unsupported command returns a NACK after the pointer, and a read or write operation with incorrect I2C address returns a NACK after the I2C address.
An I2C write sequence is performed to send a command to the HDC302x. Some of these commands also require configuration data from the I2C controller. In those instances, a CRC byte must accompany the configuration data to permit error checking by the HDC302x. Both of these I2C write scenarios are illustrated in Figure 8-3 and Figure 8-4.