The GL523SM is a temperature monitor with SMBus interface, providing the temperature measurement and over/under temperature warning for a microprocessor-based system. The device supports two channels of temperature measurement: an on-chip sensor for local and a diode-connected transistor for remote thermal zone in a microprocessor system. The thermal diode may be provided within the microprocessors to be monitored or can be a discrete NPN/PNP transistor such as the 2N3904/2N3906. The GL523SM supports two conversion modes for the supply current control: the free-running mode with adjustable conversion rate and the one-shot mode for a single conversion. All the measured values can be read out, and the values for limit comparison can be programmed via the SMBus interface.