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Scholar
Scholar
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Registered: ‎04-27-2010

AXI CDMA only works for some transfer lengths

I am using the CDMA in a design with 32-bit bus and 16 burst length max. I am trying to copy data between two buffers in DDR. If I set the transfer length to 32 or less than it works fine. Anything over 32 it just locks up. I can see that the AXI transaction is started but then just stops for some reason. Also I cant stop the Microblaze anymore (probably due to the AXI bus I guess). Anyone know what the issue with longer transfers is? Thanks 

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Scholar
Scholar
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Registered: ‎05-21-2015

@beandigital,

My guess is that something on the bus isn't obeying protocol.  Xilinx's demo designs have been known for locking up the bus for years.  You might consider placing the VIP in monitor mode on the various buses to see if the protocol is getting violated anywhere.

Were this my own project, I'd formally verify everything, then I'd be able to know which part of the design (if any) had bugs within it.

Dan

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Scholar
Scholar
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Registered: ‎04-27-2010

The thing is I am just trying to copy between two mem areas in DDR. Its not like I even have some custom IP that could be causing issues.
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Voyager
Voyager
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Registered: ‎08-02-2019

Hi @beandigital ,

What about increasing burst size to for example 23?

In this link there are some helpfull informations about parameters.

Saban

 

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