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mini-itx DDR problem

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jenn.holt's picture
jenn.holt
Junior(0)
mini-itx DDR problem

I recently purchased a mini-itx100 system and am having trouble getting it to boot. None of the pre-packaged designs seemed to word(sd card or qspi flash), but the JTAG connection works ok, so I tried building some of the reference designs.
So far the only one that works somewhat is the 'zynq_mini_itx_mem_test' part of the embedded design. This code will partially run, but it hangs any time it tries to run the DDR tests (either the PS or PL one). If I modify the code to exclude those tests, the ps7_ram test passes.
I suspect that the problem is with my DDR ram, or its configuration, since the mem_test code is not loaded in to DDR ram, and it runs fine as long as it doesn't try to access any DDR. 
I read that the newer boards have different RAM chips, (mine is revision E) but that they are not supposed to require any software changes.
Does anyone have any idea of what tests I can run to narrow down the problem?

JFoster's picture
JFoster
Moderator(48)
Hello Jenn.holt,

Hello Jenn.holt,

First I would like for you to double check that you set up your Mini-ITX properly. Go to the "Getting Started Guide" at http://zedboard.org/support/documentation/2056 and go to the "Setting up the Board" section and double check your setup. If that all checks out, check the power module and make sure it is tighly seated and the mounting screws are installed. Then check all power module voltage rails on your Mini-ITX board(we have test point and an LED for each rail) to make sure all the rails are OK.

--Josh

jenn.holt's picture
jenn.holt
Junior(0)
So I checked the setup, and

So I checked the setup, and that was OK, but there is a problem with the power supply. Test point 5 for the 1.5/1.35V rail only reads 0.6V. This is enough to weakly light the LED, so I missed it the first time around.
I checked the corresponding pin on the power supply module to rule out a bad connection, and it also reads 0.6V.
Will it damage the power supply module if I take it off and power it up unloaded?

jenn.holt's picture
jenn.holt
Junior(0)
I noticed one other thing,

I noticed one other thing, which is probably the whole problem. The power supply module has a jumper to select 1.5/1.35V and there is no jumper installed. Which voltage is appropriate for the board?

JFoster's picture
JFoster
Moderator(48)
Hello Jenn.holt,

Hello Jenn.holt,

The 1.5/1.35V is the DDR3 voltage and the jumper should be set to 1.5V for the Mini-ITX board. Let me know if this solved your problem.

--Josh

jenn.holt's picture
jenn.holt
Junior(0)
That solved it! Thanks!

That solved it! Thanks!