Patent ID: 7633965

Claim:
A data transfer control device for performing data transfer through a serial signal line, the data transfer control device comprising: a receiver circuit that receives a special code and data through the serial signal line; a serial/parallel conversion circuit that receives serial data from the receiver circuit and converts the serial data to parallel data; an idle detection circuit that detects an idle signal, a logical level of the idle signal being continuously fixed at a first logical level in units of a given number of bits or more; a decoder circuit that receives parallel data from the serial/parallel conversion circuit and performs decode processing of the data and the special code that have been encoded by using a predetermined encoding method; and a preamble error detection circuit that performs detection processing of a preamble code that is the special code and informs a preamble error when the preamble code has not been detected, the serial/parallel conversion circuit suspending operation after the idle signal has been detected by the idle detection circuit and output of parallel data from the serial/parallel conversion circuit has been completed, when a first polarity preamble code and a second polarity preamble code are transferred through the serial signal line, the preamble error detection circuit omitting detection processing of the first polarity preamble code that has been received first and performing detection processing of the second polarity preamble code that has been received after the first polarity preamble code, the polarity of the first polarity preamble code and the polarity of the second polarity preamble code being different, the first polarity preamble code and the second polarity preamble code being transferred after the idle signal, and the preamble error detection circuit performing the detection processing of the second polarity preamble code after the idle detection circuit determines that the idle signal is not detected.