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Altera_Forum
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16 years ago

External Memory Interfaces clock Critical Warning

Hi,ALL I'm trying to TimeQuest my design,but I have Critical Warings like this: "Critical Warning: Clocks driving the CK pins, write clocks pins and write data pins must use the same clock t...
Altera_Forum's avatar
Altera_Forum
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16 years ago

Globals fan out to the entire chip, but there are fewer of them and they have a longer delay(which is seldom a big deal, as skew is the main concern for globals). There are more regionals but they don't span the whole device(there are dual-regionals which do expand.) My guess is either one would work for your case. Also, I'm guessing there are transfers between the two domains. If they're on the same type of network, then the edges nicely line up, but on different networks you get large skew, and whatever interface you're doing does not want that.