An interlocked counter including a synchronous counter, a logic gate for judging end-value, a logic gate for amplifying an interlocking signal, at least one latch circuit for the interlocking signal, a logic gate for the interlocking signal, and a logic gate for an enable signal, wherein behavior of the synchronous counter is stopped when a count number arrived at an end value, by that the synchronous counter counts a number of pulses of a clock signal when the synchronous counter inputted an enable signal, the logic gate for judging end-value generates an interlocking signal when the count number outputted by a synchronous counter coincided with the end value, the logic gate for amplifying interlocking signal amplifies the interlocking signal in order to output to an external part, and the logic gate for enable signal generates the enable signal when the interlocking signal is not generated.