A semiconductor die includes first pads, switches that are electrically connected with the first pads, respectively, a test signal generator that generates test signals and to transmit the test signals to the switches, internal circuits that receive first signals through the first pads and the switches, to perform operations based on the first signals, and to output second signals through the switches and the first pads based on a result of the operations, and a switch controller that controls the switches so that the first pads communicate with the test signal generator during a test operation and that the first pads communicate with the internal circuits after a completion of the test operation.