To solve the problem that, for switching a flash ROM microcomputer for a mask ROM microcomputer in a microcomputer power supply device, if the flash ROM microcomputer and the mask ROM microcomputer use different supply voltages, the mask ROM microcomputer, a series regulator IC and a reset IC must be supplied for switching in a set to require extra supply costs, switching costs and switching man-hour requirements.
A microcomputer power supply device has a voltage setting circuit for deciding a voltage and a voltage change circuit for changing voltages to a microcomputer power supply circuit and a reset circuit simultaneously, and can thereby automatically change voltages to the microcomputer power supply circuit and reset circuit simultaneously only through a setting change of the voltage setting circuit. By this structure, the microcomputer power supply device enables simple and low cost switching from a flash ROM microcomputer to a mask ROM microcomputer.
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| JPH09153007 | BUS INTERFACE DEVICE |
| JPS57120138 | WORKING MODE DESIGNATING CIRCUIT FOR MICROPROCESSOR |
Tomoyasu Sakaguchi
Hiroki Naito
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