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Visitor
Visitor
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Registered: ‎03-15-2019

Hello World on DDR freezes

I'm working with a custom designed board that includes a Zynq 7020 connected to a Micron MT41K512M8DA-107:P DDR3 chip which has been giving me grief for a long time now. In a previous version of the design I got errors like "APB AP transaction error, DAP status f0000021" or "Memory write error at 0x100000." when attempting to run a simple Hello World on the DDR. I figured multiple things were wrong with the hardware, which led me to several fixes.

Despite that iteration, the new version of the custom board still doesnt work. I no longer recieve the error messages that I once did, but now I recieve nothing at all, it's almost as if the FPGA just freezes when I try to run anything on the DDR.

I've tried using the normal approaches to this problem: changing the DDR Configuration in the Processing System IP between all availible presets plus entering all the information about the DDR as a "Custom" part, configuring the C code to reset the system and program the ps7_init before running the code, trying to access the DDR from the XSCT window, running DDR memory tests from the RAM. Nothing seems to work.

Is there something I'm missing here? What are some common errors in custom boards with the Zynq 7020 that could produce this issue?

 

Thanks in advance.

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Moderator
Moderator
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Registered: ‎09-12-2007

This is most likely a DDR config issues, or a possible memory issue (Have you tried another part). What do you see when you run the DDR test?

 

https://www.xilinx.com/html_docs/xilinx2019_1/SDK_Doc/SDK_references/sdk_u_zynq_dram.html

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Visitor
Visitor
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Registered: ‎03-15-2019

An even eariler version of the board used a AS4C1G8MD3L-12BCN, but with the same errors. Also, these errors occur accross each of the 3 copies of the PCB design.

The DDR test gives this message:

Starting Memory Test 's' - Testing 1MB length from address 0x100000...

------------------------------------------------------------------------------------------
TEST WORD ERROR PER-BYTE-LANE ERROR COUNT TIME
COUNT [ LANE-0 ] [ LANE-1 ] [ LANE-2 ] [ LANE-3 ] (sec)
------------------------------------------------------------------------------------------

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