Title:
ELECTRONIC DESKKTOP CALCULATOR
Document Type and Number:
Japanese Patent JPS5592962
Kind Code:
A
Abstract:
PURPOSE:To eliminate the need for a time-count dedicated counter by enabing one part of an arithmetic register to serve as a counter, by counting by the arithmetic register the time between key operations, and then by stopping the power supply after a prescribed time. CONSTITUTION:Signals from ROM1 for program storage are supplied to instruction decoder 2, which is connected to arithmetic controller 3 and power-supply stop unit 4. Unit 3 is connected to ROM1 and arithmetic register 5, and power supplies to respective parts are controlled by unit 4. Since a state in which key operation is possible is not an arithmetic state but a display state, one part of register 5 which is not used during display is used to count the time between key operations and when the part is placed in a prescribed state, unit 3 generates a signal to send a power-supply stop instruction from ROM1, thereby stopping power supplies to respective parts by controlling unit 4. Consequently, the need for a dedicated counter counting the time is eliminated, and consequently the area of an integrated circuit can be reduced.
Inventors:
NAKAMURA TERUAKI
Application Number:
JP50679A
Publication Date:
July 14, 1980
Filing Date:
January 04, 1979
Export Citation:
Assignee:
NIPPON ELECTRIC CO
International Classes:
G06F15/02; (IPC1-7): G06F15/02