Patent ID: 7112989

Claim:
A transmission signal correction circuit, comprising: a first output circuit that outputs a data string to outside; a second output circuit for correction that is connected in parallel with the first output circuit, and captures the data string to add the data string to an output signal of the first output circuit during a period when a control signal is kept generated; and a data string detection circuit that generates the control signal when detecting a signal sequence, in the data string, that affects a transmission waveform, wherein the data string detection circuit generates the control signal when a data string to be sent out to the outside is obtained by multiplexing a first data string captured on a rising edge of a clock and a second data string captured on a falling edge of the clock, and when detecting a signal sequence that affects a transmission waveform, in the data string multiplexed, and the data string detection circuit includes a first flip-flop that sequentially captures bits of the first data string; a second flip-flop that sequentially captures bits of the second data string; and an exclusive OR circuit that receives outputs of the two flip-flops, and generates the control signal when a noncoincidence occurs between the outputs after they coincide with each other.