Patent ID: 7453833

Claim:
A data transmission apparatus using a serial communication interface device to perform data transmission between a master and a slave, the data transmission apparatus comprising: a data input unit for receiving at least one of transmission rate data and transmission length data to be selectively transmitted from the master to the slave; a selection unit for receiving the at least one of the transmission rate data and the transmission length data from the data input unit, and receiving at least one of a corresponding first event signal and a second event signal for instructing the writing of the at least one of the transmission rate data and the transmission length data to be selectively transmitted to the slave; a controller receiving the at least one of the transmission rate data and the transmission length data from the selection unit and for controlling a serial communication interface used to transmit the at least one of the transmission rate data and the transmission length data to the slave; and a control unit for automatically controlling critical timing of the transmission of the at least one of the transmission rate data and the transmission length data, in response to activation of the corresponding at least one first event signal and second event signal, wherein when the transmission rate data and the transmission length data are transmitted to the slave, the transmission rate data is selectively transmitted via a control path from the master to the slave during a transmission of a data frame via a data path, and the transmission length data is selectively transmitted from the master to the slave during a time interval following the transmission of the data frame.