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Altera_Forum's avatar
Altera_Forum
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16 years ago

why the twice compilation different?

I use the quartus ii 9.0 with the default configuration,nothing special. When the first compilation, i found some problems in one module, so i take some inside critial signal of this module to the...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
16 years ago

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It could be timing failures. By routing a signal differently in the 2nd compile, the re-fit could cause previously failed timing paths to pass. This usually occurs in designs that are not fully syncronous.

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Hi,

it is not only a different routing. By routing the signals to pins your are changing the synthesis itself, because this signals could not removed ( if possible) anymore. Did you have timing violations in your design ( setup or hold ) ?

Kind regards

GPK