JAJSGR1E October 2014 – September 2021 TMP102-Q1
Accessing a particular register on the TMP102-Q1 device is accomplished by writing the appropriate value to the pointer register. The value for the pointer register is the first byte transferred after the slave address byte with the R/ W bit low. Every write operation to the TMP102-Q1 device requires a value for the pointer register (see Figure 7-3).
When reading from the TMP102-Q1 device, the last value stored in the pointer register by a write operation determines which register is read by a read operation. To change the register pointer for a read operation, a new value must be written to the pointer register. This action is accomplished by issuing a slave address byte with the R/ W bit low, followed by the pointer register byte. No additional data are required. The master then generates a START condition and sends the slave address byte with the R/ W bit high to initiate the read command. See Figure 7-4 for details of this sequence. If repeated reads from the same register are desired, continuously sending the pointer register bytes is not required because the TMP102-Q1 device remembers the pointer register value until the value is changed by the next write operation.
Register bytes are sent with the most significant byte first, followed by the least significant byte.