Patent ID: 8806079

Claim:
An interface circuit for use in an electronic device, the electronic device including a first audio terminal and an audio signal providing module, the interface circuit comprising: a detecting module electrically connected to the first audio terminal, and detecting whether the first audio terminal is electrically connected to a second audio terminal of another device; a control module including a detecting pin electrically connected to the detecting module, a signal receiving pin, and a signal transmitting pin; and a switch module for establishing electrical connection between the signal receiving pin and the first audio terminal, between the signal transmitting pin and the first audio terminal, and between the audio signal providing module and the first audio terminal; wherein when the detecting module detects that the first audio terminal is electrically connected to the second audio terminal, the control module controls the switch module to establish electrical connection between the signal receiving pin and the first audio terminal, the control module further controls the switch module to establish electrical connection between the signal transmitting pin and the first audio terminal so as to proceed with a program update upon determining that updating information from the second audio terminal is received thereby through the signal receiving pin, and the control module further controls the switch module to establish electrical connection between the audio signal providing module and the first audio terminal such that an audio signal from the audio signal providing module is transmitted to the second audio terminal through the first audio terminal upon determining that no updating information is received thereby through the signal receiving pin; and wherein the switch module includes: a first switch unit for establishing electrical connection between the signal receiving pin and the first audio terminal, and between the signal transmitting pin and the first audio terminal; and a second switch unit for establishing electrical connection between the first audio terminal and the audio signal providing module; the control module controlling the first switch unit to establish electrical connection between the signal receiving pin and the first audio terminal when the detecting module detects that the first audio terminal is electrically connected to the second audio terminal and to further establish electrical connection between the signal transmitting pin and the first audio terminal upon determining that updating information from the second audio terminal is received through the signal receiving pin, the control module controlling the second switch unit to establish electrical connection between the audio signal providing module and the first audio terminal upon determining that no updating information is received thereby through the signal receiving pin.