Patent ID: 7961001

Claim:
An impedance adjusting device, comprising: a calibration node coupled to a first impedance; a comparison unit configured to compare a reference voltage with a voltage of the calibration node; a counting unit configured to generate an impedance code according to a comparison result of the comparison unit; a reference impedance unit connected to the calibration node and configured to have an impedance value according to the impedance code; a storage unit configured to store the comparison result of the comparison unit upon the generation of the impedance code being completed; an interface node; and a termination unit configured to receive the impedance code and the comparison result stored in the storage unit and terminate the interface node, the termination unit including a plurality of parallel resistors and an additional parallel resistor, wherein an overall impedance value of current paths through the plurality of the parallel resistors is adjusted according to the impedance code and an impedance value of a current path through the additional parallel resistor is adjusted according to the comparison result stored in the storage unit, wherein the comparison result stored in the storage unit has information as to which of an impedance value of the first impedance at the calibration node and the impedance value of the reference impedance unit is larger after the generation of the impedance code has been completed.