Patent ID: 7769914

Claim:
An electronic device having a universal serial bus interface, comprising: first and second data paths for inputting data signals from a first pad; third and fourth data paths for inputting complementary data signals of the data signals from a second pad, said first and third data paths supporting data signals compatible with an inter-chip USB interface standard and said second and fourth data paths supporting data signals compatible with a USB 2.0 standard; a first switch for selecting one of the first data path and the second data path in accordance with a selection signal; a second switch for selecting one of the third data path and the fourth data path in accordance with the selection signal; a detection circuit configured to generate the selection signal having a value that specifies whether the data signal and complementary data signal are compatible with the inter-chip USB interface standard or the USB 2.0 standard, said detection circuit comprising a reference voltage generator configured to generate a reference voltage having a magnitude that reflects a high level of a signal on a data path and a comparator configured to generate the selection signal in response to comparing the magnitude of the reference voltage with a voltage level of a power supply voltage from a power pad; and a controller configured to receive the data signal selected by the first switch and the complementary data signal selected by the second switch and further configured to process the data signal and the complementary data signal in response to the selection signal.