| 摘要 |
<p>PURPOSE:To adjust the clock frequency by constituting a ring oscillator formed by a gate circuit having a delay corresponding to a gate delay of a clitical path for determining an operation threshold in an IC, as a clock generating circuit in the IC, and controlling a power supply voltage of its oscillator. CONSTITUTION:A ring oscillator is constituted of a gate circuit having a delay corresponding to a gate delay time of a path in which a gate delay in an IC becomes maximum, that is, a clitical path. This ring oscillator is incorporated to the IC 5 as a clock generating circuit 6. In such a state, a frequency of a clock is adjusted due to a fact that a power supply voltage supplied to the ring oscillator is controlled. In such a way, the frequency of the clock can be adjusted, an optimal frequency can be selected, and a margin of a period of the clock against the date delay can be set to a necessary minimum and optimal state.</p> |
