Patent ID: 8283809

Claim:
A detecting device for detecting an operating mode, comprising: a pulse generator, for issuing a one-shot pulse signal in response to each of a plurality of button signals respectively; and a hold-up unit, for receiving the button signals to respectively generate delayed button signals by way of clock delay determined by a clock signal, each delayed button signal uniquely corresponding to one of the button signals, wherein the hold-up unit comprises hold-up circuits, respectively receiving the button signals and generating the delayed button signals, wherein one of the hold-up circuits comprises: a latch circuit, for generating a corresponding delayed button signal, wherein one input of the latch circuit is able to be triggered by a first edge of a corresponding button signal such that a level of the corresponding delayed button signal is changed to and latched at a first level; and a clock delay circuit for receiving the clock signal, wherein, after the clock delay circuit is triggered by a second edge of the corresponding button signal and a predetermined time period determined by the clock signal has elapsed, the clock delay circuit triggers another input of the latch circuit to change the level of the corresponding delayed button signal to a second level; wherein the one-shot pulse signal and the delayed button signals are used to determine an operating mode of a system.