Possible to "guess" the memory interface from boar

tb

Newcomer
Hi!

I've a question:

Is it possible to determinate the memory interface width from the board layout and the memory modules?


r200vsr300.jpg

R300 vs. FireGL 8800

There are a lot more "small parts" surrounding the R300 memory modules...

R300_RAM.jpg

R300 memory modules (What does the 214 mean? Found no infos in the specs)

parhelia_BGA.jpg

Parhelia memory modules (What does the 214 mean? Found no infos in the specs)

Thomas
 
I don't want to speculate about the memory interface.

0214 does likely mean "produced year 2002, week 14".

Pretty much every IC I've seen has the production date printed on it that way.
 
Probably not, since most of the traces are going to be in the inner layers of the board.

But, I suppose it may be possible if you know the bandwidth of the individual chips. I don't know enough about DDR memory signalling to know for sure how to find it out from that, however.
 
You can't necessarily tell if you know the memory modules' interface bus width, since often chips share a bus (as on the Ti4600 - two modules share a 32-bit bus).

You can tell the difference between a 128-bit bus and a 256-bit memory bus though, despite traces being on internal layers. Look for groups of SMT resistors in packs of 4, inline with the memory traces. These are serial and active termination components (the very latest memory modules actually have them integrated into the package) and there should be twice as many on a 256-bit bus compared to a 128-bit bus. You can see them pretty clearly on this pic of R300...

R300BGA.jpg


MuFu.
 
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