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Altera_Forum
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17 years ago

Output IO Buff is too large; DDR3

Hello, I downloaded and ran the altdq_dqs example from Altera literature webside. The example claimed these IO BUFFs could handle up to 333.333 MHz (3ns), but I found that their output B...
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Altera_Forum
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17 years ago

Your document is very useful. It is great. Thanks.

I followed your document instruction, but cannot figure out where you come up 0.927ns setup slack and 0.861ns hold slack from the below statements.

if we look at case# 3. our clock is 5ns (200mhz), so we know our setup and hold requirements are +/-1.25ns. if i enter all set_output_delay constraints as 0ns, i get a worst setup slack 0.927ns and a worst hold slack of 0.861ns. taking the smaller of these two, i set my constraints to: