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Altera_Forum
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15 years ago

DDR PIN placement error

Hi all, I use a Cyclone IV E EP4CE40F23C8 with Quartus 11.0 I have this error message when i try to place ddr pins --- Quote Start --- Error: altmemphy pin placement was...
Altera_Forum's avatar
Altera_Forum
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15 years ago

It also happened to me. During layout we inadvertently made a few wrong swappings ...

Now the Cyclone IV manual states that the DQS are not used for capture, as there is no DLL circuitry on-board. The ALT-MemPHY uses a dedicated capture clock (that one it phase-shifts to make up for PVT-variations).

I didn't see any special silicon for the DQS/DQ/DM pins, so in theory any IO pin should be able to serve the purpose. Is there a document that reveals the DQ/DQS/DM mysteries, why they are fixed to these 'exact' locations ?