MIG (Memory Interface Generator)

[mariuszgrad]

Hi,

S6 can support memory densities up to 4Gb.

Can someone recommend 4Gb memory device which is proven to work correctly?

Greetings, Mariusz.

[robinliuy · Accepted solution]

Hi,

Try to customize a 4Gb device based on a 2Gb device which has same timing paremeters with 4Gb device.

[darrenger]

Mariusz - have you had any luck getting a 4GB device to work since your post?  Any advice, suggestions on doing so would be greatly appreciated.

Thanks,

Darren

[mariuszgrad]

Hi darrenger,

Nope, I haven't tried.

I just talked with guys who design starter kits about it and they said that they don't know anyone who tried this.

They said that they have designs with 2GB modules and they do work.

The other thing with 4GB module is that one has to remember that it will fill out whole memory address space for 32 bit CPU.

In other words if you will use Microblaze or PowerPC than you will have problems to get access to peripherals with this module.

I asked about that in this forum so you can try to find the answers.

Greetings, Mariusz.

[darrenger]

Thanks for your reply Mariusz.

At present I am trying to get a 2GB module to work by manually adjusting the parameters in a working 512 MB MIG design.  The reason I am trying to modify the 512 MB design is that I am having no luck with the 2GB design I generate from scratch using MIG; I do not seem to be able to get any initialization signal in the example design MIG itself generates.  If you have any insight about how to get a working 2GB MIG design, or even if you have access to a working 2GB ref design (I am using ML605 board), I'd be very happy to hear back from you.

Thanks again,

Darren

[mariuszgrad]

Hi Darren,

Unfortunately I do not have any ref design which could help you.

Are you using certificated DIMM?

You can find the list on page 35 of UG388.pdf

Greetings, Mariusz.

[eteam00]

Are you using certificated DIMM?

You can find the list on page 35 of UG388.pdf

I don't believe Spartan 6 MCB supports DIMMs or SO-DIMMs, only base DRAM components are supported, up to 2Gbit density.  Maximum data bus width to DRAM is 16 bits.  UG388 applies to only Spartan 6.

If you're discussing 4Gb or DIMMs (or SO-DIMMs), you are probably referring to Virtex 6 -- but UG388 isn't applicable for V6 designs.

From Mariusz' original post in this thread:

S6 can support memory densities up to 4Gb.

I believe this is incorrect.  Limit for S6 is 2Gb, not 4Gb.

- Bob Elkind

[mariuszgrad]

You are right.

I misinterpreted ML605 as S6 and the max capacity is 2Gb (ug388 / p.35).

Thanks for pointing out.

Greetings, Mariusz.

[darrenger]

Thanks guys,

To clarify: I'm trying to get a 4GB SO-DIMM module working on the ML605 board (Virtex-6) by using a mig-generated memory controller.  So far, I've been able to get a 512 MB module working using Xilinx's MIG reference design.  Unfortunately, I cannot get either of my 2GB or 4GB memory modules to even initialize, much less test that they are useful.  I'm wondering if anyone has any advice on either adjusting an already working MIG design to handle higher memory densities or getting Xilinx's MIG-generated "example-designs" functioning properly.

Thanks again for your help,

Darren

[eteam00]

I think your first step is to get a MIG--generated 512MB design to work.  From what you've written, there are two potential problems to overcome:

1.  Get ANY MIG-generated design to work on ML605 board

2.  Get 4GB target to work (vs. 512MB)

Since you have a working example (at 512MB), you have a reference for comparison.  Generate a 512MB target design with MIG, and compare the MIG output with the reference design MIG-generated files.  It's likely that the MIG-generated files need to be "massaged" to fit the ML605 target board, and those manual post-processing steps haven't been done (this just a guess on my part, I don't have an ML605 to back this up).

-- Bob Elkind