Electronic device, electronic system, and method for processing signals from an audio accessory thereof

An electronic system, comprising:

• an audio accessory, comprising:
• an audio plug, comprising a first pin for transmitting a first channel signal, a second pin for transmitting a second channel signal, a third pin coupled to a ground terminal, and a fourth pin for transmitting an audio input signal;
• an audio output unit, coupled to the first pin and the second pin, arranged for outputting the first channel signal and the second channel signal;
• an audio input unit, coupled to the fourth pin, arranged for receiving the audio input signal;
• and
• a control element, coupled between the audio input unit and the fourth pin of the audio plug, comprising at least one button;
• and
• an electronic device, comprising:
• an audio jack, comprising a first terminal corresponding to the first pin of the audio plug, a second terminal corresponding to the second pin, a third terminal corresponding to the third pin, and a fourth terminal corresponding to the fourth pin, wherein the electronic device connects with the audio plug of the audio accessory via the audio jack;
• a power supply unit, coupled to the fourth terminal of the audio jack, arranged for providing a first voltage to the fourth terminal of the audio jack and a second voltage when the audio accessory connects to the electronic device;
• a determining circuit, coupled to the power supply unit and the fourth terminal of the audio jack, arranged for receiving the second voltage and a third voltage, and for determining whether to trigger an interrupt request according to the second voltage and the third voltage, wherein the third voltage is coupled to the fourth terminal and is generated according to the first voltage;
• and
• an executing circuit, coupled to the determining circuit and the power supply unit, arranged for determining whether to execute a corresponding function according to the third voltage when the interrupt request is received to enable the executing circuit to detect the third voltage.

A method for processing signals from an audio accessory, applied to an electronic device comprising an audio jack for connecting with the audio accessory, the audio jack comprising a terminal for transmitting an audio input signal, the method comprising the following steps:

• when the audio accessory connects to the electronic device, providing a first voltage and a second voltage;
• determining whether to trigger an interrupt request according to the second voltage and a third voltage, wherein the second voltage is coupled to the terminal and is generated according to the first voltage;
• and
• determining whether to execute a corresponding function according to the third voltage when the interrupt request is received to enable detection of the third voltage.