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Altera_Forum's avatar
Altera_Forum
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9 years ago

How to utilize programmable delay chain?

Greetings, I'm using a Cyclone IV, and I have a bi-directional DDR data strobe line that I am using to clock in data (clock in when I'm performing a read. I am basically using this documen...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
9 years ago

Enabling that D1 setting seemed to not make a difference. I did check the fitter report, but everything has a delay chain value of 0ps ...

So I am betting that I am doing something horribly wrong. Either I don't have some tool settings enabled, my input register structure makes it impossible to apply a programmable delay (I'm using ALTDDIO_BIDIR as the input register, or my timing constraints are so bad that the tools immediately give up on trying to meet timing.

I did manage to make a minimalist project that replicates my problem. I just deleted every single thing ezcept this input clocking structure. Maybe someone can check it out?