Data transmission/reception system and data reception device

An image forming apparatus that is provided with a data reception device for receiving serial data including a plurality of frames which each include synchronization data and effective data, the data reception device comprising:

• a reception clock signal generator which generates a reception clock signal whose frequency is approximately equal to a frequency of a transmission clock signal, the reception clock signal being asynchronous to the transmission clock signal;
• a delayed clock signal outputting unit which outputs, in accordance with the synchronization data, a delayed clock signal whose phase approximately matches a phase of the transmission clock signal, the delayed clock signal being created by delaying a phase of the reception clock signal;
• an adjustment amount obtaining unit which obtains a phase adjustment amount according to a frequency difference of the reception clock signal with the transmission clock signal;
• and
• a setting unit which sets a synchronization clock signal for capturing effective data included in each of the plurality of frames, in accordance with the phase adjustment amount and the delayed clock signal.

A data reception device for receiving serial data including a plurality of frames that each include synchronization data and effective data, the data reception device comprising:

• a reception clock signal generator which generates a reception clock signal whose frequency is approximately equal to a frequency of a transmission clock signal, the reception clock signal being asynchronous to the transmission clock signal;
• a delayed clock signal creating unit which delays a phase of the reception clock signal to create a plurality of delayed clock signals that are equal to the reception clock signal in frequency and different from the reception clock signal in phase;
• an adjustment amount computing unit which computes a phase adjustment amount according to a frequency difference of the reception clock signal with the transmission clock signal;
• and
• a selecting unit which selects, in accordance with the phase adjustment amount, one of the plurality of delayed clock signals as a synchronization clock signal for capturing effective data included in each of the plurality of frames.

An image forming apparatus that is provided with a data reception device for receiving serial data including a plurality of frames which each include synchronization data and effective data, the data reception device comprising:

• a reception clock signal generator which generates a reception clock signal whose frequency is approximately equal to a frequency of a transmission clock signal, the reception clock signal being asynchronous to the transmission clock signal;
• a delayed clock signal creating unit which delays a phase of the reception clock signal to create a plurality of delayed clock signals that are equal to the reception clock signal in frequency and different from the reception clock signal in phase;
• an adjustment amount computing unit which computes a phase adjustment amount according to a frequency difference of the reception clock signal with the transmission clock signal;
• and
• a selecting unit which selects, in accordance with the phase adjustment amount, one of the plurality of delayed clock signals as a synchronization clock signal for capturing effective data included in each of the plurality of frames.

A data reception method for receiving serial data including a plurality of frames that each include synchronization data and effective data, the data reception method comprising the steps of:

• a) generating a reception clock signal whose frequency is approximately equal to a frequency of a transmission clock signal, the reception clock signal being asynchronous to the transmission clock signal;
• b) delaying a phase of the reception clock signal to create a plurality of delayed clock signals that are equal to the reception clock signal in frequency and different from the reception clock signal in phase;
• c) computing a phase adjustment amount according to a frequency difference of the reception clock signal with the transmission clock signal;
• d) selecting, in accordance with the phase adjustment amount, one of the plurality of delayed clock signals as a synchronization clock signal for capturing effective data included in each of the plurality of frames;
• and
• e) capturing the effective data according to the synchronization clock signal.