| 摘要 |
PROBLEM TO BE SOLVED: To enable effectively using a deskew time at the time of deskew where fine adjustment is performed, by absorbing irregularity of propagation delay time of a CMOS device which is generated between the respective pins in two steps of rough adjustment and fine adjustment. SOLUTION: Delay time adjusting circuits 3 are connected in series with deskew circuits 4. In the delay time adjusting circuits 3, the unit time of variable delay amount of the deskew circuits 4 is set large in order to adjust the propagation delay time of rough level which cannot be adjusted with the deskew circuits 4. Before deskew, a pin whose propagation delay time is the largest is detected with a time measuring device 12. The delay time of the pin is compared with delay times of other pins, and rough adjustment wherein the delay times of other pins are made to coincide with the delay time of the pin whose delay time is the largest is performed. After that, fine adjustment by deskew is performed.
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