A pulse edge selection circuit includes an input stage which selects and passes one clock from among a plurality of clocks and an output stage which outputs the clock to an edge detection circuit. The output stage has a combination of a plurality of NOR gates and a plurality of NAND gates, which are connected alternately, both the NOR gates and NAND gates having a plurality of input terminals. If the edge detection circuit is a type which detects falling edges of clocks and generates a pulse which rises on the falling edge of a first clock and falls on the falling edge of a second clock, a NOR gate is used as an output gate which outputs the first clock and the second clock. On the other hand, if a pulse is generated on rising edges, a NAND gate is used as an output gate.