Microcomputer

Abstract

Abstract PURPOSE:To reduce the power consumption from the time of the stand-by mode by controlling connection or disconnection of feedback resistances of all oscillating circuits in a microcomputer incorporating plural oscillating circuits. CONSTITUTION:When an oscillating circuit for a high frequency will be used, a connection control signal 15 is set to the low level to disconnect a feedback resistance 14 from terminals 16 and 17. Consequently, a current path passing the resistance 14 is eliminated when the terminal 16 is set to the low level; and if the oscillating circuit for the high frequency is stopped in the stand-by mode, the power consumption of the whole of the microcomputer is about zero. Meanwhile, when the microcomputer will be operated in a low-power consumption state, a connection control signal 10 is set to the low level to disconnect the current path of a feedback resistance 9, and the signal 15 is set to the high level to connect a crystal oscillator for a low frequency to terminals 16 and 17 and an oscillation signal is obtained, thereby using it as the system clock of the microcomputer.

Inventors

• 👤 Hiroshi Hikichi
• 👤 博 引地

Bibliographic Details