BACKGROUND OF THE INVENTION

Field of the Invention

The invention relates to a control circuit, and more particularly to a control circuit that is coupled to a display device and a touch device.

Description of the Related Art

With technological development, the types and functions of electronic devices have increased. Generally, each electronic device has at least one input device and at least one output device. A control device in a corresponding electronic device controls the operation of the electronic device according to the information received by the input device. The control device displays the corresponding image via the output device. The touch device is a common input device. The display device is a common output device. However, since the touch device and the display device have more input-output pins, the number of pins in the control device must be greater than the sum of the number of input-output pins in the touch device and the display device so that the control device can be coupled to the touch device and the display device. Therefore, the space in the electronic device is reduced.

BRIEF SUMMARY OF THE INVENTION

In accordance with an embodiment, a control circuit comprises a first input-output pin, a second input-output pin, a sensing circuit and a display controller. The first input-output pin is configured to be coupled to a first input pin of a display device and a first sensing pin of a capacitive touch device. The second input-output pin is configured to be coupled to a second input pin of the display device and a second sensing pin of the capacitive touch device. The sensing circuit determines whether the capacitive touch device is touched according to the voltage of the first input-output pin and the voltage of the second input-output pin. The display controller provides a first driving signal to the display device via the first input-output pin and providing a second driving signal to the display device via the second input-output pin in a display period. In a first sensing period, the voltage level of the first input-output pin is equal to a first predetermined level, and the sensing circuit detects the voltage of the second input-output pin.

In accordance with another embodiment, a display apparatus comprises a display device, a capacitive touch device, and a control circuit. The display device comprises a first input pin and a second input pin. The capacitive touch device comprises a first sensing pin and a second sensing pin. The control circuit comprises a first input-output pin, a second input-output pin, a sensing circuit, and a display controller. The first input-output pin is configured to be coupled to the first input pin and the first sensing pin. The second input-output pin is configured to be coupled to the second input pin and the second sensing pin. The sensing circuit determines whether the capacitive touch device is touched according to the voltage of the first input-output pin and the voltage of the second input-output pin. The display controller provides a first driving signal to the display device via the first input-output pin and providing a second driving signal to the display device via the second input-output pin in a display period. In a first sensing period, the sensing circuit sets the voltage level of the first input-output pin to a first predetermined level and detects the voltage of the second input-output pin.

