Control device for controlling a central processing unit on instantaneous voltage drop

Claim 1

A control device for controlling a central processing unit in accordance with an input voltage which is applied to said central processing unit and which is supplied by a power source having a power source voltage, said central processing unit having a first terminal for receiving a first signal to make said central processing unit assume a first state and a second terminal for receiving a second signal to make said central processing unit assume a second state, said control device comprising: input voltage applying means connected to said power source for applying said input voltage to said central processing unit, said input voltage applying means being responsive to a first detection signal for stopping applying said input voltage to said central processing unit; first detecting means for detecting whether said power source voltage is lower than a first voltage and produce said first detection signal when said power source voltage is lower than said first voltage; first delay means for delaying said first detection signal during a first delay time and supply said first signal to said first terminal; second detecting means for detecting whether said input voltage is lower than a second voltage which is lower than said first voltage, said second detecting means supplying said second signal to said second terminal when said input voltage is lower than said second voltage; and a charging means coupled to said power source and said processing unit for charging an electric charge, said charging means discharging said electric charge to apply a charged voltage to said central processing unit when said input voltage applying means stops applying said input voltage to said central processing unit.