Method of spreading spectrum of data transmission clock and device for the method

A device that performs data communication with a counterpart device via a transmission channel, the device comprising:

• a PLL configured to modulate and output a frequency of a clock used to synchronize communication data in accordance with a regulation signal applied thereto,
• a second PLL configured to modulate and output a frequency of a second clock recovered from the digital signal, which is used to capture and receive a digital signal from a signal carried on the transmission channel, in accordance with a second regulation signal applied thereto,
• a first controller configured to generate a first regulation signal according to a modulation waveform which is a successive form of a plurality of modulation wave units determined by a set modulation profile, and apply the first regulation signal to the first PLL,
• a delay unit configured to delay the first regulation signal by a delay time according to a delay control signal applied thereto and output it as the second regulation signal,
• a tracker configured to regulate a delay time of the first regulation signal in the delay unit according to a signal-to-noise ratio of a data stream recovered from the digital signal, and apply the delay control signal corresponding to the regulated delay time to the delay unit, and
• a main controller configured to control the first controller so that application of the first regulation signal to the first PLL is started, and configured to include wherein the modulation wave unit is a signal whose sum of signal values during its time length becomes zero for the first time, and configured to include a main controller configured to control the tracker to start regulation of the delay time for the first regulation signal.

A method for communicating data with a counterpart device via a transmission channel, the method comprising:

• confirming the set modulated wave data,
• setting a modulation waveform as the modulation profile, the modulation waveform being a form in which a plurality of modulation wave units indicated by the confirmed modulation wave data are successively formed, and
• generating a regulation signal according to the modulation waveform and apply the regulation signal to a PLL configured to modulate and output the frequency of a clock used to synchronize communication data,
• wherein the PLL is configured to modulate the frequency of the clock according to the regulation signal,
• wherein the modulation wave unit is a signal whose sum of signal values over the time length becomes zero for the first time, and
• wherein at least two successive modulation wave units among the plurality of modulation wave units differ from each other in at least one of the time length and the form of the signal.