Patent ID: 8558905

Claim:
A transmission device comprising: a transceiving unit which transceives a serial signal which is generated by serially converting data based on a clock signal of a frequency selected from a plurality of frequencies used as clock components of the serial signal and includes the clock signal of the selected frequency; a clock recovering unit which receives the serial signal received by the transceiving unit and recovers a recovered clock signal from the serial signal; a match determination unit which receives the recovered clock signal recovered by the clock recovering unit and determines whether or not a frequency of the recovered clock signal matches each of the plurality of frequencies; a frequency controller which, if the match determination unit determines that the frequency of the recovered clock signal matches each of the plurality of frequencies, performs a control to determine the frequency of the recovered clock signal recovered in the clock recovering unit as the matching frequency; and a converting unit which serially converts data based on the clock signal to transmit the serially converted signal to the transceiving unit, wherein the frequency of the recovered clock signal recovered in the clock recovering unit is switched between the plurality of frequencies until the frequency is determined by the frequency controller, wherein the converting unit converts a predetermined command data corresponding to a predetermined one of the plurality of frequencies based on the clock signal of the determined frequency and transmits the converted command data from the transceiving unit, and if there is a predetermined response to the command data, the frequency of the clock signal used by the converting unit is switched to the predetermined frequency.