A circuit according to an embodiment of the present invention comprises a
first power supply region supplied with a first power supply voltage, and
having a first clock distribution network, a second power supply region
supplied with a second power supply voltage, and having a second clock
distribution network, a PLL circuit which provides a first output signal
obtained by making a phase of a reference clock signal for controlling a
data input/output coincident with a phase of a clock signal at an end
point of the first clock distribution network, to a start point of the
first clock distribution network, and a PLL circuit which provides a
second output signal obtained by making the phase of the reference clock
signal coincident with a phase of a clock signal at an end point of the
second clock distribution network, to a start point of the second clock
distribution network.