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Altera_Forum
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12 years ago

De 3 pin assignment challenge

I implemented a simple logic(AND gate) and from my observation, apart from LED (LEDR(7)) that was assigned for output another LED (LEDR(4)) would come on alongside. In addition the 2-input AND gate s...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
12 years ago

Thanks for that info.... but do u know how i can set the DE3 board to be driven from the anode side. Regarding the I/O assignment, my top level I/O names are assigned and that output pin indicates (cathode driven), however a pin assigned to unknown name by the compiler (ASSIGNMENT>PINS>ASSIGNABLE PINS) comes up alongside.

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I guess the LEDs on DE3 board are driven from the cathode side, like in most designs. So, they turn on when the driving output is low and the NAND behaviour you observe is pretty normal. Regarding the I/O assignment, open the Quartus pin assignment editor and check if your top level I/O names match with the assigned ones.

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