Output driver for controlling impedance and intensity of pre-emphasis driver using mode register set

摘要

An output driver controls impedance using a mode register set. The output driver includes a main driving circuit that outputs and drives a main signal based on a data signal to a predetermined transmission line, an auxiliary driving circuit that outputs and drives an auxiliary signal to the transmission line, and a mode register set. The mode register set generates an impedance control signal group, a driving width control signal group and a delay control signal group. The amount of an auxiliary impedance (SIM), and the driving width and driving time point of an auxiliary signal (XSDR) can be controlled using the impedance control signal group, the driving width control signal group and the delay control signal group. Therefore, in accordance with the output driver of the present invention, the amount of output impedance (OIM), a pre-emphasis width and a pre-emphasis time point can be readily controlled, and the efficiency of the transmission of an output signal to a reception system is improved.