Semiconductor device compensating for internal skew and operating method thereof

A method for compensating for an internal skew of a semiconductor device having first and second receiving units and operating based on a synchronous clock, the method comprising:

• generating a reference signal;
• transmitting the reference signal to the first and second receiving units to generate first and second output signals;
• generating first sampling data by sampling the second output signal based on the first output signal;
• generating a delayed signal by delaying the first output signal by a delay time;
• generating second sampling data by sampling the second output signal based on the delayed signal;
• comparing the first and second sampling data;
• and
• determining a delay time of a delay unit according to a result of the comparing.

A method of compensating for an internal skew of a semiconductor device operating based on a synchronous clock, the method comprising:

• generating a reference signal;
• transmitting the reference signal to a plurality of receiving units of the semiconductor device, a first receiving unit among the receiving units receiving the synchronous clock and the other receiving units receiving respective input data;
• controlling each of the receiving units to select and output the reference signal;
• comparing at least one of reference signals output from the other receiving units to a reference signal output from the first receiving unit;
• and
• according to a result of the comparing, controlling the at least one of the reference signals to further delay or advance in view of the reference signal output from the first receiving unit, thereby compensating for a skew between the synchronous clock and the data.