Impedance controllable ouput drive circuit in semiconductor device and impedance control method therefor

摘要

A drive circuit having impedance control includes an impedance matching array unit having a plurality of transistors, the plurality of transistors selectively driven in accordance with an array drive control signal generated by control code data, and an update prohibition control unit for generating a transfer control signal to prohibit driving the transistors during a first time interval occurring when internal data transition, and applying the transfer control signal to the impedance matching array unit.