| 摘要 |
PURPOSE:To change oscillation frequency at an arbitrary time, by an execution program of a microcomputer system. CONSTITUTION:When an output 40 of an oscillation frequency control FF21 is at high level, an N-MOS TR18 is conductive. Thus, at the oscillation of a CMOS oscillation circuit, a capacitor 11 is charged through a P-MOS TR14, discharged through a resistor 13 and N-MOS TRs 16, 17, 18 and then the oscillation frequency is controlled. Next, when the output 40 of the FF21 is changed to a low level, the N-MOS TR18 is non-conductive. With this state, the capacitor 11 of the CMOS oscillation circuit is made through the resistor 13 and the N-MOS TR16. Set input signal I1 and reset input signal I2 for an oscillation frequency control FF21 are generated with the clock alteration instruction of a microcomputer system. |
