Patent ID: 7173964

Claim:
A method for detecting data transmission rate of a Universal Serial Bus (USB) controller by using a USB device having at least one program storage device, said method comprising: executing a detecting program stored in said program storage device, the detecting program including the steps of: a. activating a timer via an interrupt request signal; b. setting a data transmission rate of said USB device in a full-speed mode upon a failure to detect a USB chirp K signal transmitted from said USB controller within a pre-determined period of time; c. if said USB chirp K signal transmitted from said USB controller is detected within said pre-determined period of time, setting said data transmission rate of said USB device in a full-speed mode upon a failure to detect a USB chirp J signal within said pre-determined period of time; d. if said USB chirp J signal transmitted from said USB controller is detected within said pre-determined period of time, repeating the method at steps b and c twice; and e. setting said data transmission rate of said USB device in a high-speed mode if said data transmission rate is not set in said full-speed mode.