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5145 Discussions

altmemddr with 4GB SO-DIMM on DE3

Honored Contributor I



I have DE3 board and wish to install 4GB SO-DIMM into this board. 


As I understand, I need to use Altmemddr (please, correct me if I am wrong!). When I start this megawizard, I cannot find any reasonable configuration for 2 or 4 Gb memory slots. 


Would somebody suggest me, please: 


1. what kind of memory of SO-DIMM 4Gb DDR2 from what company etc should I use, 

2. where I can find corresponding data for these memory and how to install this information into Altmemddr. 


Or, if my way of development is incorrect, please, advise me what should I do to use about 4Gb external memory on DE3 board? 


PS: for my current test I need only to exchange SODIMM memory (read or write) by large continuous peaces of data like m9k or m144k blocks. 




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4 Replies
Honored Contributor I

I think, it wouldn't mean expecting too much to ask Terasic for a functional example od SO-DIMM usage with DE3, if it isn't already shipped with the board. 


4GB SODIMM should be exchangeable between manufacturers, acceptable documentation is e.g. provided by Micron or Samsung. The memory PHY configuration is similar to that for the respective discrete chips with byte organization.
Honored Contributor I

Dear FvM, 


thank you for answering! 


Actually I asked Terasic (it was about 3 months ago), and got the following answer: 


> We are afraid all of DE3 design examples incorporate the Nios II processor into their design. 


It was not very helpful for me, because available examples: 


1. works only with 1 GB, and the is no access to source or to Altmemddr to modify it to 4 Gb, 


2. require NIOS, and it takes about 2MBit of M9K/M144K memory blocks that is unacceptable for my design. 


However, may be, in the mean time, Terasic has something new and I will definitely ask them again :) 


Would you please suggest me from what point to start in case if Terasic still has nothing for my case? 


I know that DDR2 is constructed with pages, generally I can implement it by myself, because I need only few amount of operations: 

1. init one block for reading, 

2. read the block, 

3. close it, 

4. recover blocks, 

5. init one block for writing, 

6. write the block, 

7. close it. 


Actually I know the theory, but I did not implemented it yet, hence, any tips to do it will be very helpful! 


PS: indeed if somebody can share me module for Altmemddr it will be perfect and I will continue to work with my project. 




Honored Contributor I

altmemddr isn't but a preconfigured version of the DDR2 High Performance Controller. If you want to use the DDR2 RAM wiithout SOPC, you should instantiate the HP controller directly. You can however export some setting from the SOPC altmemddr instance.

Honored Contributor I

I roughly understand what you are saying, but it does not help me to solve my problem :) Anyhow thank you for your answer!