JPS5680731A - Key input circuit - Google Patents
Key input circuitInfo
- Publication number
- JPS5680731A JPS5680731A JP15861179A JP15861179A JPS5680731A JP S5680731 A JPS5680731 A JP S5680731A JP 15861179 A JP15861179 A JP 15861179A JP 15861179 A JP15861179 A JP 15861179A JP S5680731 A JPS5680731 A JP S5680731A
- Authority
- JP
- Japan
- Prior art keywords
- signals
- timing
- circuit
- input
- closed
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Input From Keyboards Or The Like (AREA)
Abstract
PURPOSE: To prevent noises, generated mutually when one equipment is incorporated in the other equipment, from appearing at the key input circuit of an electronic watch, etc., by connecting switch contacts between electrodes wired in a matrix shape and by detecting key operation with a timing signal.
CONSTITUTION: When none of switches SW1WSW9 is closed, timing signals T1W T3 stay at level "1" and only when one of SW1WSW9 is closed, a signal is applied to one of input signals I1WI3 with the timing of signals T1WT3. Simultaneously, the operations of timing generating circuit 1 and memory circuit 2 are stopped and output signals S1WS9 of input dividing circuit 3 are fixed. When the closed switch is opened, circuits 1 and 2 restart to operate and the signals are not outputted from input dividing circuit 3 any more. Thus, noises can be eliminated and an increase in the number of terminals of LSI can be suppressed.
COPYRIGHT: (C)1981,JPO&Japio
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP15861179A JPS5680731A (en) | 1979-12-05 | 1979-12-05 | Key input circuit |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP15861179A JPS5680731A (en) | 1979-12-05 | 1979-12-05 | Key input circuit |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS5680731A true JPS5680731A (en) | 1981-07-02 |
JPS6149688B2 JPS6149688B2 (en) | 1986-10-30 |
Family
ID=15675483
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP15861179A Granted JPS5680731A (en) | 1979-12-05 | 1979-12-05 | Key input circuit |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS5680731A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS60142414A (en) * | 1983-12-29 | 1985-07-27 | Fujitsu Ltd | Method for controlling reading of key switch |
JPH01178633U (en) * | 1988-06-09 | 1989-12-21 |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS63182622A (en) * | 1987-01-26 | 1988-07-27 | Omron Tateisi Electronics Co | Projector |
-
1979
- 1979-12-05 JP JP15861179A patent/JPS5680731A/en active Granted
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS60142414A (en) * | 1983-12-29 | 1985-07-27 | Fujitsu Ltd | Method for controlling reading of key switch |
JPH01178633U (en) * | 1988-06-09 | 1989-12-21 |
Also Published As
Publication number | Publication date |
---|---|
JPS6149688B2 (en) | 1986-10-30 |
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