The LM32 is a digital temperature sensor that measures 3 temperature zones and has a single-wire interface compatible with National Semiconductor's SensorPath bus. SensorPath data is pulse width encoded, thereby allowing the LM32 to be easily connected to many general purpose micro-controllers. Several National Semiconductor Super I/O products include a fully integrated SensorPath master, that when connected to an LM32 can realize a hardware monitor function that includes limit checking for measured values, autonomous fan speed control and many other functions. The LM32 measures the temperature of its own die as well as two external devices such as a processor thermal diode or a diode connected transistor. The LM32 can resolve temperatures up to 255°C and down to -256°C. The operating temperature range of the LM32 is 0°C to +125°C. The address programming pin allows two LM32s to be placed on one SensorPath bus.