Preventing flow of current from sub-CPU to main-CPU during power saving mode in an image forming apparatus

摘要

An electronic device, comprising: an execution unit which executes a predetermined function; a first control unit that has an input terminal and causes the execution unit to execute the predetermined function; a power source unit that supplies power at least to the first control unit; and a second control unit that has an output terminal connected to the input terminal of the first control unit via a signal line, operates to output a signal to the first control unit via the signal line, and causes the power source unit to cut off power supply to the first control unit, and wherein the second control unit keeps a potential of the signal line at a reference level lower than or equal to a predetermined threshold while the second control unit causes the power source unit to cut off power supply to the first control unit.