Patent ID: 7184484

Claim:
A method for serial data communication which transmits and receives data in two-way, comprising: transmitting data and a separate clock signal from a first control unit to a second control unit, at the same time checking a reception confirmation signal of the second control unit by the first control unit, wherein said transmitting data from the first control unit further includes the steps of: confirming whether data was received, starting the data transmission with a data transmission start signal, and receiving the reception confirmation signal from the second control unit; recognizing the data reception of the second control unit, and reversing the transmission start signal in order to transmit a next data; transmitting a transmission permission signal which permits the next data transmission to the first control unit by the second control unit; and feedback-receiving the transmission permission signal; wherein a size of the transmitted data is adjusted voluntarily in accordance with communication circumstances, and is determined in accordance with a data processing unit of the second control unit, and; transmitting data and a separate clock signal from the second control unit to the first control unit, at the same time checking a reception confirmation signal of the first control unit by the second control unit by checking the separate clock signal from the first control unit.