Reg - DDR2 Interfacing with AM335X.

Hi,

There is no AM5533 processor in the Sitara family. I suppose you are asking about AM335X. Please see section 5.7 from the AM335X Datasheet Rev. H, the second table gives values for DDR2. You will see that Vih is referenced to DDR_VREF, which is half the DDR supply voltage (Note that Vil is missing from this table, this is a documentation error which will be corrected in the next release, and Vil max. voltage is DDR_VREF - 0.125V)

So, to answer your question you can replace Vtt with DDR_VREF for your analysis.

HI, Thanks for reply. I am using AM3352. I understand you answer.
My question was that in Micron(MT47H64M16NF-25E: M ) DDR2 datashseet, It is mentioned that Voh and Vol is VTT+0.603 and VTT-0.603. As per AM533 datasheet we dont need VTT termination for DDR2. I need to ask how we can complete noise margin analysis if VTT is not given. What value i should consider for VTT if we are not using VTT termination for calculating Voh and Vol.

Please read my answer above:

"So, to answer your question you can replace Vtt with DDR_VREF for your analysis."

ok. Thanks for your reply

Make sure you also check datasheet section 7.7.2.2.2.9 DDR2 Signal Termination when designing your DDR2 interface.