mentioned reference value To are recorded. 3032 to 303n respectively designate registers, wherein reference value 2To to nTo are stored. 303A refer to and-gates connected to the output terminals of the registers 303, one of the input terminals of each of which is connected to the output terminal 1O of the abovementioned decoder 304D. 3032A to 303nA respectively designate and-gates, one of the inpu