The TMP112 family supports the SMBus alert function. When the TMP112 family operates in interrupt mode (TM = 1), the ALERT pin can be connected as an SMBus alert signal (when the ALERT pin is available). Irrespective of the availability of the ALERT pin, the alert status is set. When a controller senses that an alert condition is present on the alert line, the controller sends an SMBus ALERT command (0001 1001) to the bus. If the ALERT pin is active or the alert is set, the device acknowledges the SMBus ALERT command and responds by returning the target address on the SDA line. The eighth bit (LSB) of the target address byte indicates if the alert condition is caused by the temperature exceeding T_(HIGH) or falling below T_(LOW). The LSB is high if the temperature is greater than T_(HIGH), or low if the temperature is less than T_(LOW). Refer to the Figure 7-6 section for details of this sequence.

If multiple devices on the bus respond to the SMBus ALERT command, arbitration during the target address portion of the SMBus ALERT command determines which device clears the alert status of that device. The device with the lowest two-wire address wins the arbitration. If the TMP112 family wins the arbitration, the TMP112 family ALERT pin becomes inactive and/or clears the status bit at the completion of the SMBus ALERT command. If the TMP112 family loses the arbitration, the TMP112 family ALERT pin and/or the status bit remains active.