Patent ID: 8654377

Claim:
A data communication device comprising: a communication execution unit operable to execute serial communication of an asynchronous type and receive serial communication data from a remote communicating party; a bit variance detection block operable to: detect a variance between bits in the received serial communication data, wherein the detected variance comprises a transition from a low-level bit to a high-level bit in a word of the serial communication data; and generate one or more interrupt signals based on a position of the transition from the low-level bit to the high-level bit in the word of the serial communication data, wherein said generated one or more interrupt signals cause a timer to initiate and terminate time measurement to measure a low-level pulse width of the word of the serial communication data; and a control unit operable to: recognize a transmission speed of the serial communication data based on a confirmation whether the measured low-level pulse width is equivalent to a predefined width of one or more bits of one of low-speed communication data or high speed communication data; and discriminate a start bit and a first data bit in the word of the serial communication data based on the recognized transmission speed.