I2C is a serial bus interface to common types of low data rate peripheral chips.

I guess you mean "brown-out" detector. This would be a circuit that detects when the the Vcc of the processor goes just low enough that the processor cannot be exppected to operate reliably. The normal control mechanism under these instances is to assert a hard RESET signal to the processor. This function is typically provided by a RESET GENERATOR chip or a MICROPROCESSOR SUPERVISOR chip.

Michael Karas