A method of interrupt control for a control unit of an electronic system includes receiving digital data; determining a value of the digital data; and sending interrupt signals to a host by the following methods according to the value: when the control unit is in a second signal sending status and after the value of the digital data increases to be greater than a first threshold and remains greater than the first threshold for a first period of time, switching the control unit to a first signal sending status; and when the control unit is in the first signal sending status and after the value of the digital data decreases to be smaller than a second threshold and remains smaller than the second threshold for a second period of time, switching the control unit to the second signal sending status. The second threshold is smaller than the first threshold.