Patent ID: 7130184

Claim:
A portable terminal communicably coupled to an external accessory, the external accessory being one of a plurality of external accessories, each of the plurality of external accessories being a different type and having differing functions, wherein at least one of the plurality of external accessories comprises an earphone having an earphone function, wherein each of the plurality of external accessories comprises a resistance value that corresponds to a type of external accessory, comprising: an earjack comprising a plurality of communicable contacts for communicably coupling the external accessory via two or more of the plurality contacts, wherein a number of contacts used and a usage of each contact varies depending on the type of the communicably coupled external accessory, and further wherein one of the two or more contacts is an analog-to-digital conversion (ADC) contact used exclusively for detecting a resistance value of the communicably coupled external accessory; an ADC section for converting a resistance value of the communicably coupled external accessory into an ADC value; a memory for storing ADC reference values that correspond to resistance values of the plurality of external accessories; and a controller for controlling the ADC section to convert the resistance value of the communicably coupled external accessory into an ADC value, determining the type of the communicably coupled external accessory by comparing the converted ADC value with the ADC reference values stored in the memory, controlling the number and usage of the plurality of contacts to correspond to the communicably coupled external accessory, and performing a function of the communicably coupled external accessory.