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Visitor ygtygr
Visitor
5,324 Views
Registered: ‎11-16-2009

EXCEPTION_ACCESS_VIOLATION & Speed

Hello,

I am getting EXCEPTION_ACCESS_VIOLATION on Isim on Xilinx Webpack 11.1.

I was able to get rid of the problem by stripping off some part of my netlist and replacing it with some generate command which does the same thing,but now I am stuck.

I have already read all sections I could find about this error and other fatal errors including "http://www.xilinx.com/support/answers/30913.htm" but they didnt help.

Also I have some speed issues when it doesnt crash.

Can you point me in the right direction?

My questions are

1- I am using a 32-bit operating system and CPU, would you recommend to use a 64-bit system + CPU? (So I could use a larger RAM)

 

What made me think it is a RAM issue is crash log:

 

 "Exception at PC 0x1000707D

Attemped to write at address 0x0000003C

Printing stacktrace...

 

Done"

 

2- My code is about 20000 line including (testbench + netlists) so it should be ok to work with a webpack without any limitation as far as I got it as it is well below 50000 lines, but it takes ages to simulate or even check syntax. Would it be any faster with a full version of ISE?

 

Thanks is advance

 

Yigit

 

 

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2 Replies
Xilinx Employee
Xilinx Employee
5,319 Views
Registered: ‎08-15-2007

Re: EXCEPTION_ACCESS_VIOLATION & Speed

Yigit,

 

We apologize for the inconvenience this issue has caused.

 

1) EXCEPTION_ACCESS_VIOLATION fatal errors are indeed typically due to memory access issues.  Some things to consider:

    a) Turn off multi-threading.  Refer to Solution 2 in Xilinx AR 32357 to see if this resolves the issue.

    b) Native 64-bit support is only available in supported Linux OS (RHEL 5).  64-bit support in Windows OS will be available in ISE Design Suite 12 (Spring 2010).  If you have a 64-bit RHEL machine available, you are encouraged to run your simulation in that environment.  

 

 2) Check whether this warning in shown during simulation:

 

"This is a limited version of the ISE Simulator. The current design has exceeded the design size limit for this version and the performance of the simulation will be derated. Please contact your nearest sales office at www.xilinx.com/company/contact.htm or visit the Xilinx on-line store at www.xilinx.com/onlinestore/design_resources.htm if interested in purchasing the full, unlimited version of this simulator".

 

If so, you should be able to observe better performance with ISE Simulator included in the ISE Design suites.  Otherwise, you have not reached the performance threshold and thusly you would encounter the same performance with ISim Full.  

 

Xilinx is working in improving the performance of ISE Simulator.  If possible, please provide the design in question via a WebCase so Technical Support can gauge the performance issues for future enhancements.

 

 

  
 

 

 

 

Eddie
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Visitor ygtygr
Visitor
5,304 Views
Registered: ‎11-16-2009

Re: EXCEPTION_ACCESS_VIOLATION & Speed

Hello Eddie,

 

Thank you for quick response.

 

This time I could accidentally solve the problem by getting rid of a circular reference warning which actually wasn't circular referencing, but I will be trying your suggestions for future problems.

 

Thanks 

 

Yigit

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