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  3. internal exception Large VHDL Memory

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internal exception Large VHDL Memory

SaiGautamJP
SaiGautamJP over 3 years ago

Hello,

I am using cadence Xcelium  for simulation and as I run the elaboration step, i am seeing the following message and the simulation process stops - 

xmelab: *W,LARGEM: Large VHDL memory (134217728 >= 2^25) declared (file: ahb_monitor.vhd, line: 62). You may hit system virtual memory exceeded issues.

xmelab: *F,INTERR: INTERNAL EXCEPTION
-----------------------------------------------------------------
The tool has encountered an unexpected condition and must exit.
Contact Cadence Design Systems customer support about this
problem and provide enough information to help us reproduce it,
including the logfile that contains this error message.
TOOL: xmelab(64) 20.09-s006
HOSTNAME: rt-xicrh7-6
OPERATING SYSTEM: Linux 3.10.0-1160.41.1.el7.x86_64 #1 SMP Mon Aug 16 14:52:32 UTC 2021 x86_64
MESSAGE: cu_vhdl_sig_ptrblk_setdummysize(): Dummy sigsize setting botch
-----------------------------------------------------------------
csi-xmelab - CSI: Cadence Support Investigation, sending details to /projects/me158/me158aa/jps2rt/current/database_bosch_ip/gtm/sim_data/xmelab_27442.err
csi-xmelab - CSI: investigation complete, send /projects/me158/me158aa/jps2rt/current/database_bosch_ip/gtm/sim_data/xmelab_27442.err to Cadence Support
class AST_S_IF has parent of class AST_S_IF
xrun: *E,ELBERR: Error during elaboration (status 255), exiting.
TOOL: xrun(64) 20.09-s006: Exiting on Feb 09, 2022 at 11:11:24 CET (total: 00:01:35)
gmake: *** [makefile:151: compile_tb] Error 1

Any help on how to proceed would be appreciated.

Thank you.

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  • StephenH
    StephenH over 3 years ago

    I suspect that the crash happens due to the system running out of memory, in light of the *W,LARGEM warning before it. Can you try elaborating the design with the option -vhdlsparsearray to see if that helps?

    You can also reference the docs for this: Elaboration Command-Line Options -- VHDL Options - 4.17 -vhdlsparsearray value

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  • SaiGautamJP
    SaiGautamJP over 3 years ago in reply to StephenH

    Hello Stephen, thank you for your suggestion. I read through the documentation and used the -vhdlsparsearray option. It seems to still show the large memory warning but without an internal exception. 

    Unfortunately I haven't been able to prove that this option is the solution because after I used this option, it seems to work also without this option.

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  • StephenH
    StephenH over 3 years ago in reply to SaiGautamJP

    I suspect that you were unlucky with your first simulation, and some other process was also taking a lot of RAM, so the host machine ran out of RAM sooner. I would still recommend using the -vhdlsparsearray option because it should reduce the peak RAM requirement of your simulation anyway, meaning you're less likely to hit issues.

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  • SaiGautamJP
    SaiGautamJP over 3 years ago in reply to StephenH

    OK I understood. Thank you very much for your support!

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