Patent ID: 7495469

Claim:
An on-die termination circuit comprising: a control unit for sequentially generating a plurality of control signals in response to a driving signal; a termination resistance supply unit for supplying a termination resistance in response to a coarse code signal having a plurality of bits and a fine code signal having a plurality of bits; and a code signal generating unit for controlling the fine code signal and the coarse code signal in response to the plurality of the control signals so that the termination resistance has a level which corresponds to an input resistance, wherein the code signal generating unit includes: a code signal generation control unit for outputting a level signal which corresponds to a difference between the fine and coarse code signals and the input resistance in response to the corresponding control signal; a register control unit for activating a first driving signal in response to a first control signal and for activating a second driving signal when the level signal goes from a first logic level to a second logic level; a coarse code register for generating the coarse code signal corresponding to the level signal in response to the first driving signal; and a fine code register for generating the fine code signal corresponding to the level signal in response to the second driving signal.