An ALERT signal is an interrupt line for devices that want to trade their ability to master for a pin. ALERT is a wired-AND signal as SCL/SDA. A slave-only device can signal the host through the ALERT signal that it wants to talk. Routing it to the PMBus connector allows the Fusion GUI to monitor and display the ALERT pin state. This signal is optional and does not have a communication function, but it is recommended. Some users may use the ALERT pin as a fault source to shut down the system, but it is not recommended. Many other conditions can assert the ALERT pin, such as communication error and log full. The UCD90240, UCD90320 and UCD90320U devices support the SMBALERT_MASK command, which may be used to prevent a warning or fault condition from asserting the SMBALERT signal.
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