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Altera_Forum
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14 years ago

Using the SDRAM on the DE2-115 without NIOS, only HDL language

Hello,

I am currently trying to implement a dual-port RAM in the DE2-115 evaluation board, using the 2x64 MB SDRAM chips. I do not want to use NIOS or SOPC builder at all, only using HDL language.

At first I thought that the Altera Megafunction where suppose to do it but since there was no pin assignment to do I got sceptical and then understood that is was for the memory block of the Cyclone IV chip.

Then I took a look at the datasheet of the SDRAM chip and also at the Quartus II handbook about the HDL coding style while interfering with memory modules but I am confused with all the different commands and operation that needs to be done to use the SDRAM (compared to a simple SRAM for example).

As I already lost too many times already, I am wondering if somebody knows where I can find somekind of manual/tutorial, like the following link: ftp://ftp.altera.com/up/pub/altera_material/9.1/tutorials/vhdl/de2-115/using_the_sdram.pdf but without NIOS processor as I don't want to use it.

Or in the worse case where I would need to do everything myself, is there some tips that needs to be known while using SDRAM or should I just apply "stupidly" the truth table of the SDRAM pins for the required operation (read/write)?

Thank you in advance,

Meach

12 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    If You don't understand the way SDRAM works - the only solution to Your problem is memory megacore. It does all the required precharge/read/write stuff, so read the docu and it will be much easier to work. Also check the reference designs how SDRAM pins are constrained. Usually, MegaWizard generates a script which does all the job for constraints, You just need to specify locations.

  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    Hi there,

    I'm currently stucked in the same problem, I'm trying to use the SDRAM of my DE2-115.

    my first try has been reading datasheet and doing my own controller, but is a mess.

    I understand the way sdram works, but I'm geting mad with the vhdl programation, is there a vhdl example or tutorial?

    Also, if use megacore, wich one is the one I need? because i tried two of them and i was unsuccessful tu make it work, I discard all the DDR (is this ok?) the issi sdram isn't a DDR

    Thanks,

    Guillermo
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    That ISSI chip isn't SDRAM chip at all. Not even talk about DDR SDRAM. Its SRAM, so You don't need any SDRAM controllers for that!

  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    Issi is42s16320B datasheet says it's a 512Mbit Synchronous DRAM,

    there is an issi sram also, but I'm not interested in sram
  • Altera_Forum's avatar
    Altera_Forum
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    13 years ago

    Meach,

    Which core did you end up using for your project? Did you use an Altera core, write one yourself, or use something else? Opencores?
  • Altera_Forum's avatar
    Altera_Forum
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    13 years ago

    What do you need the SRAM for? Please note, that the DE2-115 has both SDRAM and SRAM.

    SRAM reqires a straight forward memory mapped interface (only).
  • Altera_Forum's avatar
    Altera_Forum
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    12 years ago

    I'd like to revive this page. Someone might have new answers about this. I've just realized that the SDRAM in DE2-115 is not a DDR one so none in the MegaWizard IP works.

    In this tutorial, the SDRAM was used along side NIOS. I don't want to use NIOS like the thread starter. ftp://ftp.altera.com/up/pub/altera_material/12.0/tutorials/vhdl/de2-115/using_the_sdram.pdf

    Any insights on how to implement the SDRAM without NIOS?

    In Chapter 9: Implementing and Parameterizing Memory IP 9–3 Design Flow of this handbook (http://www.altera.com/literature/hb/external-memory/emi_plan.pdf), it showed two possible ways to generate the IP. One using the Qsys and the other using the MegaWizard. Can someone share their knowledge on how to create a complete IP of the SDRAM Controller using Qsys with AVALON interface as the controlling component?
  • Altera_Forum's avatar
    Altera_Forum
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    12 years ago

    You might try starting with an example that uses NIOS. Then remove the NIOS and drive the SDRAM controller directly.