SBOS581B September 2011 – June 2022 TMP100-Q1 , TMP101-Q1
PRODUCTION DATA
Accessing a particular register on the TMP100-Q1 and TMP101-Q1 devices is accomplished by writing the appropriate value to the Pointer Register. The value for the Pointer Register is the first byte transferred after the I2C target address byte with the R/ W bit LOW. Every write operation to the TMP100-Q1 and TMP101-Q1 devices requires a value for the Pointer Register (see Figure 7-4).
When reading from the TMP100-Q1 and TMP101-Q1 devices, the last value stored in the Pointer Register by a write operation is used to determine 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 an I2C target address byte with the R/ W bit LOW, followed by the Pointer Register Byte. No additional data are required. The controller can then generate a START condition and send the I2C target address byte with the R/ W bit HIGH to initiate the read command; see Figure 7-5 for details of this sequence. If repeated reads from the same register are desired, the Pointer Register bytes do not have to be continually sent because the TMP100-Q1 and TMP101-Q1 devices remember the Pointer Register value until that value is changed by the next write operation.