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Altera_Forum
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14 years ago

CLKIN Pin as General Purpose Input

I'm doing a Cyclone III design (simulation only, no hardware yet) and am using one of the dedicated clock input pins as a general purpose input. It compiles OK & meets timing constraints so I'm assu...
Altera_Forum's avatar
Altera_Forum
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11 years ago

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Why can't I really use the CLKIN pin as a output?

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Because the pin on the FPGA is a dedicated clock input pin which does not support output. Search for "dedicated clock input pin" in the Cyclone II handbook.

If you just want to use the given pin(s) on the connector so you can drive your old board, find another pin/net you don't care about and solder a wire to the connector.