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Altera_Forum
Honored Contributor
Honored Contributorwhen OR gates work as AND gates.!? NEEK
ok, I know its been a few years since I went to school but has someone redefined how OR gates work.!?
(See attached) So I have two buttons on my NEEK connected to a OR2 gate. The output drives an led. so problem is you have to press BOTH to get the led to come on. I then tried swapping out the OR2 gate with an AND2 gate - guess what, either button lights the led.!?:confused: Any comments welcome. Thanks Paul Quartus 9.1 Build 222 Web Edition WinXP SP24 Replies
Altera_ForumRetry it with primitive AND, OR, instead of LPM_AND LPM_OR
- Altera_Forum
Did you check the logic sense of your switches and LEDs??
- Altera_Forum
Ha-ha-!! :D
Yes its the logic on the buttons and leds. Buttons when pressed pull down and leds are pull down. Thanks for pointing out the obvious - silly me! Many thanks Paul :) - Altera_Forum
Congratulations, you have just discovered de morgan's laws (http://en.wikipedia.org/wiki/de_morgan%27s_laws) the hard way!
