CLOCK OSCILLATION CIRCUIT

PURPOSE:To constitute easily a system with less power consumption by providing the circuit stopping generation of the clock of a basic clock oscillation circuit or inhibiting an output therefrom and a circuit releasing the stop or inhibition. CONSTITUTION:When power is applied, an initial state setting circuit 6 is activated to initialize a selection circuit 3 and a release command circuit 5 so as to allow the basic oscillation circuit 1 generating a clock signal to make oscillation. The circuit 3 inhibits the output of the clock from a clock output circuit 2 until the oscillation of the circuit 1 is stabilized and when the oscillation is stabilized, the circuit 2 outputs the clock. When signals I2, I3 are inputted in this state, an inhibition circuit 4 generates a signal stopping the clock signal or inhibiting the clock output. The operation of the signal is decided depending on the state of the input signal I1 so that the oscillation of the circuit 1 is stopped or the output at the circuit 2 is inhibited. When a signal I4 is inputted in this state, the circuit 5 generates a signal stopping oscillation or releasing the clock output inhibiting state to output the clock signal.