Patent ID: 7161854

Claim:
A data delay control apparatus, comprising: a selection device configured to select and output one of a strobe signal and a reference clock in accordance with a selection signal; first and second delay elements, each configured to receive and delay the strobe signal and the reference clock by a prescribed value; a phase comparing device configured to compare phases of outputs of the first and second delay elements; a delay value changing device configured to change the prescribed delay value of the second delay element; and a prescribed number of flip-flops, each configured to input data upon receiving the strobe signal from the second delay element, said prescribed number corresponding to a number of data inputs; wherein said second delay element delays the strobe signal by the prescribed delay value and outputs the delayed strobe signal to the flip-flops when the selection device selects the strobe signal, and wherein said phase comparing device compares reference clocks output from the first and second delay elements, and said delay control device changes the prescribed delay value of the second delay element in accordance with the comparison result of the phase comparing device when the selection device selects the reference clock.