PURPOSE: To secure resetting when a power switch is turned on at a terminal device which uses a microprocessor, by providing a monitoring control circuit which holds a voltage applied to the reset terminal of a CPU below a level L from the operation of a power switch to a rise of a CPU voltage to an operation securing voltage, or at a level H after resetting is completed.
CONSTITUTION: A terminal device which uses a microprocessor (MPU) is provided with a voltage monitoring control circuit which holds a voltage to be applied to the reset terminal of the CPU1 of the MPU below a level L from the operation of a power switch SW to a rise in CPU's voltage to an operation securing voltage, or at a level after resetting operation is completed between a power source and the reset terminal of the CPU. Consequently, when a user turns on the power switch, the resetting is secured even if chattering is generated at the contact owing to a way of operating, or in case of repetitive on-off operation.
JP2022108530 | UNINTERRUPTIBLE POWER SOURCE SYSTEM |
JPS6159460 | HIGH VOLTAGE POWER SOURCE FOR ELECTROSTATIC CHARGING |
YOSHIDA MITSUO
MATSUURA ATSUSHI
NIPPON TELEGRAPH & TELEPHONE
HASEGAWA DENKI SEISAKUSHO