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dnovick
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Registered: ‎06-16-2016

XMD MRD always returns 0

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I am using a Zed Board.

 

I am working on a design that shares memory between the PS and PL via block RAM. In my PL, I read and write data to BRAM in my PL as well as my PS. I confirm my memory writes by reading the block ram and outputting the LSBs to the LEDs.

 

Reads and writes are working as expected.

 

However, when I try to do memory reads via XMD, I always get 0. I can do memory writes via XMD, and they work fine (I can see the output on the LEDs). This seems very strange to me...especially since it just started happening. 

 

I have looked at both my HW and SW design...and frankly, I see no reason for this to be happening. My design is pretty much a POC at this point and is quite simple.

 

Any ideas what's going on?

 

Dave

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dnovick
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Registered: ‎06-16-2016

So, I believe I have found the problem. I had followed a tutorial for configuring the UART1 manually, instead of using the board preset. In that demo, the only thing they do is a Hello World output to stdout. It works fine. In my new design, I did the same thing. I turned the board preset off and configured UART1 and the DDR manually. This apparently causes problems once I add BRAM.

 

I went back and configured the ZYNQ to use the board presets. Now both this problem as well as my stdout problem (separate post) is fixed.

 

I have another problem that has resulted, but I will look into that myself for now.

 

Dave

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dnovick
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Registered: ‎06-16-2016
One update. I see the exact same behavior with XSDB.
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dnovick
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7,760 Views
Registered: ‎06-16-2016

So, I believe I have found the problem. I had followed a tutorial for configuring the UART1 manually, instead of using the board preset. In that demo, the only thing they do is a Hello World output to stdout. It works fine. In my new design, I did the same thing. I turned the board preset off and configured UART1 and the DDR manually. This apparently causes problems once I add BRAM.

 

I went back and configured the ZYNQ to use the board presets. Now both this problem as well as my stdout problem (separate post) is fixed.

 

I have another problem that has resulted, but I will look into that myself for now.

 

Dave

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