Key input circuit

Details Key input circuit Key input circuit

1987-08-12

1989-10-31

Lall, Parshotam S.

Coded data generation or conversion

Bodily actuated code generator

Including keyboard or keypad

341 25, G06F 300

Patent

active

048780561

ABSTRACT:
A plurality of key switches are provided, each of which is connected, at one end, to the ground, and at the other end, to a power supply, by means of a resistor. The key switches are coupled, at the connection point with the resistor, to input buffers. Each input buffer outputs an electrical signal when the corresponding key switch is turned on. A counter circuit is provided for counting clock signals supplied from a CPU at predetermined intervals. The output data of this counter circuit is supplied to selectors, which select one of the input buffers, in accordance with the output data of the counter circuit, and supply the output signal of the selected input buffer to the CPU.

REFERENCES:
patent: 3613054 (1971-10-01), Ricard
patent: 3706973 (1972-12-01), Acquadro et al.
patent: 4040036 (1977-08-01), Hester
patent: 4079234 (1978-03-01), Kashio
patent: 4303907 (1981-12-01), Wilson
patent: 4318087 (1982-02-01), Wilson
patent: 4360913 (1982-11-01), Struger et al.
patent: 4485455 (1984-11-01), Boone et al.
patent: 4513394 (1985-04-01), Deyer
patent: 4538027 (1985-08-01), Deyer
The TTL Data Book.COPYRGT.1985, pp. 3-493 to 3-497 and 3-1055 to 3-1063, Texas Instruments.
"An Introduction to Digital and Analog Integrated Circuits and Applications, " by Sanjit Mitra, Harper & Row Publishers, .COPYRGT.1980, pp. 75-82, 87-88, 466.

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