Patent ID: 8291127

Claim:
A circuit for controlling a peripheral device interface to enable a central processing unit (CPU) to detect a peripheral device normally, the circuit comprising: first to sixth capacitors; and a control chip comprising: a power supply input pin connected to a power supply, and grounded via the first and second capacitors in parallel to make voltages and currents of the power supply input pin stable; a first differential signal output pin connected to the peripheral device interface via the third capacitor; a second differential signal output pin connected to the peripheral device interface via the fourth capacitor; a first differential signal input pin connected to the peripheral device interface via the fifth capacitor; a second differential signal input pin connected to the peripheral device interface via the sixth capacitor; and an expansion pin grounded via a resistor to provide stable voltages and currents between each of the first and second differential signal output pins, the first and second differential signal input pins, and the peripheral device interface; wherein when the peripheral device is connected to the peripheral device interface, the control chip receives a detection command from the CPU, and converts the detection command into an electronic signal and sends the electronic signal to the peripheral device interface via the third and fourth capacitors stably, the peripheral device interface returns a notifying signal to the CPU via the fifth capacitor, the sixth capacitor, and the control chip to enable the CPU to detect the peripheral device.