Patent ID: 7724040

Claim:
An overclock control circuit for a central processing unit (CPU) comprising: an RC circuit, an input terminal of the RC circuit connected to a signal pin of a network indicating lamp to receive a pulse signal, the RC circuit converting the pulse signal to a direct current (DC) voltage; a first comparator circuit, an input terminal of the first comparator circuit connected to an output terminal of the RC circuit to receive the DC voltage; a second comparator circuit, an input terminal of the second comparator circuit connected to the output terminal of the RC circuit to receive the DC voltage; a first switch circuit, an output terminal of the first comparator circuit connected to an input terminal of the first switch circuit, an output terminal of the first switch circuit connected to a first clock pin of a clock chip; and a second switch circuit, an output terminal of the second comparator circuit connected to an input terminal of the second switch circuit, an output terminal of the second switch circuit connected to a second clock pin of the clock chip; wherein when a network has little traffic, the signal pin of the network indicating lamp outputs a high level signal, the first and second comparator circuits output control signals to control the first and second switch circuits to output low level signals to the first and second clock pins of the clock chip, to prevent the CPU from overclocking; when the network has medium to high traffic, the signal pin of the network indicating lamp outputs a pulse signal with a low frequency, the first and second comparator circuits output control signals to control the first and second switch circuits to output a high level signal and a low level signal respectively to the first and second clock pins of the clock chip, to control the CPU to automatically overclock by a predetermined intermediate amount; and when the network is overloaded, the signal pin of the network indicating lamp outputs a pulse signal with a high frequency, the first and second comparator circuits output control signals to control the first and second switch circuits to output high level signals to the first and second clock pins of the clock chip, to control the CPU to automatically overclock by large predetermined amount.