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Altera_Forum's avatar
Altera_Forum
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14 years ago

Number of RUP, RDN pairs for SO-DIMM?

How many RUP,RDN resistor pairs would need to be connected when using termination calibration blocks for a 64-bit DDR SO-DIMM? I would like to add these resistors to my next board spin but I'm not qu...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

In the Arria II GX specs doc it states that only one calibration block is needed as long as all of the blocks being calibrated have the same VCCIO. We have an Arria II GX board with 4 discrete DDR2 chips and we only needed 1 set of RUP RDN resistors.

From page 6-26:

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You can configure I/O banks to receive calibrated codes from any OCT calibration block with the same VCCIO. All I/O banks with the same VCCIO can share one OCT calibration block, even if that particular I/O bank has an OCT calibration block.

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