| 摘要 |
PROBLEM TO BE SOLVED: To reduce the initialization cycle of impedance matching in an interface buffer, and to suppress influence on other circuits as much as possible when making fine adjustment afterward. SOLUTION: A semiconductor device 1 comprises the interface buffers 18a-18c in which internal impedance is adjusted by impedance adjustment data, and an impedance adjustment circuit 35 for generating the impedance adjustment data. The impedance adjustment circuit has a first impedance adjustment mode for initially generating the impedance adjustment data, by dichotomizing search comparison operation in a prescribed impedance adjustment increment for setting in the interface buffer; and a second impedance adjustment mode for updating the impedance adjustment data set in the interface buffer, by successive comparison operation in the prescribed impedance adjustment increment. COPYRIGHT: (C)2005,JPO&NCIPI
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