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Altera_Forum's avatar
Altera_Forum
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14 years ago

Useful clock skew

I'm running some very small blocks through Quartus to give an idication on their timing. We are running off an 8ns clock. The problem is that the clock skew in the timing reports is at nearly 3ns, wh...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

Thanks for the reply.

Yes I expect some clock skew but I thought around 3ns was a little bit on the large side. Should I expect this much even for a small block when targeting a large Stratix IV device? Maybe the logic is spread out around the massive expanse of the device?

Is this the fitter/timer using deliberate useful clock skew?

If it is can I turn it off?

At the end of the day it's not the end of the world as it's just a case of picking out the data delay from the reports - just thought it would be useful to turn it off if I could.

I'll try your suggestion of double registering I/O - thanks.