PURPOSE: To reduce the noise voltage due to the discharging current for the change of the output voltage from the high level to the low level to prevent the malfunction of a semiconductor device by providing a circuit which detects the change of continuously and periodically outputted data from the high level to the low level between the preceding cycle and the current cycle.

CONSTITUTION: Circuits 8c to 8e, 10f, 16a to 16d, 17, and 18 are provided which detect that output data in a certain cycle and that in the next cycle of output data are binary code '1' and '0' respectively. The timing of the change from '1' to '0' of output data of at least one output circuit Dout1 is shifted from those of output circuits Dout2 to Doutn parallel with the output circuit Dout1. The output circuit Dout1 is provided with detecting circuits 8c to 8e, 10f, 16a to 16d, 17, and 18 which detect the change from the high level to the low level in this manner. Thus, the noise voltage due to the discharging current for the change from the high level to the low level of the output voltage is reduced to prevent the malfunction of the semiconductor device.