Semiconductor device

A semiconductor device comprising:

• a slew rate controller configured to receive mode register set signal and data, and to active a driving strenght control signal for controlling driving strenght of a driving unit using the data in response to a code value of the mode register set signal;
• and
• the driving unit configured to pull a data output terminal up and down in response to the driving strenght control signal.
• wherein the slew rate controller includes:
• a pull-up slew rate controller configured to receive the mode register set signal and data, and to active a pull-up driving strength control signal for controlling the driving strength of a pull-up driving unit using the data in response to the mode register set signal code value;
• and
• a pull-down slew rate controller configured to receive an inverted mode register set signal and data, and to active a pull-down driving strength control signal for controlling the driving strength of a pull-down driving unit using the data in response to the inverted mode register set signal code value,
• wherein the driving unit includes:
• a pull-up driving unit configured to sequentially pull the data output terminal up in response to the pull-up driving strength control signal;
• and
• a pull-down driving unit configured to sequentially pull the data output terminal down in response to the pull-down driving strength control signal,
• wherein the pull-up driving unit includes N pull-up devices, the pull-down driving unit includes N pull-down devices, the pull-up driving strength control signal is configured to turn a specific number of the pull-up devices on according to the mode register set signal code value, and the pull-down driving strength control signal is configured to turn the specific number of the pull-down devices on according to the mode register set signal code value,
• wherein the mode register set signal code consists of 2 bits, the specific number of the turned on devices is N/2 in a first operation mode in which the bits have values of different levels, and the specific number of the turned on devices is N in a second operation mode in which the bits have values of the same level, and
• wherein the pull-up driving strength control signal includes data and N/2−1 pull-up delayed signals in the first operation mode and data and N/2 pull-up delayed signals in the second operation mode, and the pull-down driving strength control signal includes data and N/2−1 pull-down delayed signals in the first operation mode and data and N−1 pull-down delayed signals in the second operation mode.