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Global reset promotion

Altera_Forum
Honored Contributor II
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Hello, 

 

Is there a reason why high-fanout synchronous reset is not promoted to global signal network automatically (Quartus 11.1)?  

"Global & Other Fast Signals" report shows only 3 global signals used.  

My synchronous reset shows up first under "Non-global high fanout signals" with highest fanout among non-global signals. 

 

This is for Stratix V device. I could not find in the documentation how many global signals it can have but I recall that Stratix II had about 16 of them so SV should not have less I guess. 

 

Regards, 

Michal
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Altera_Forum
Honored Contributor II
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There are a lot of rules and the tools don't always do what you want. If you think it should be there, make a global assignment. It's always worth seeing what Quartus does and then deciding if another method is better. (You're definitely not running out...) 

One thought is timing. Getting onto a global is not necessarily very fast. Also, is it a full design? If you have only 3 globals, I'm guessing it's not, and hence the fan-out may not be large enough to really need a global. As I said, there are a lot of things Quartus uses in the decision process, and in the end there are often things that I would do differently.
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