Provided are a semiconductor device and a method for inputting and outputting data simultaneously through a single bi-directional pad. The semiconductor device includes a bi-directional input/output pad including an output buffer and an input buffer, a data output line coupled to the output buffer, and a data input line coupled to the input buffer. A bit line sense amplifier is coupled to a plurality of bit lines. A first switching circuit is coupled to the data output line. And a second switching circuit is coupled to the data input line.