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cosx's avatar
cosx
Icon for Occasional Contributor rankOccasional Contributor
5 years ago
Solved

STA failed during rapid recompilation

Hi everyone, I came across a strange problem in Quartus 15.1 standard edition. The error is at rapid recompilation step whenever I add instrument circuits in the old design. This error is shown bel...
  • Nurina's avatar
    Nurina
    5 years ago

    Hi,


    I was able to reproduce your problem in Quartus Standard version 15.1.2, but not in the later versions. Unfortunately our engineering team does not support Quartus Standard version 15.1.2 anymore so I cannot report this problem to them.


    I suggest you migrate to Quartus Standard v19.1 as the error does not arise in this version. This is the latest version of Quartus Standard that still support OpenCL. Also since you're using ALTERAOCLSDKROOT in your design it needs to be changed to INTELFPGAOCLSDKROOT as it has been upgraded in v19.1.


    Regards,

    Nurina


Nurina's avatar
Nurina
Icon for Regular Contributor rankRegular Contributor
5 years ago

Hi Mingqiang,


The workaround you mentioned for v19.1 is meant for a different Internal Error.


Can you provide your project file so I can reproduce your error?


Thanks,

Nurina


cosx's avatar
cosx
Icon for Occasional Contributor rankOccasional Contributor
5 years ago

Hi Nurina,

Thank you very much for your reply!

I firstly correct myself that at the full compilation stage this error occurs, not just at rapid recompilation.

The original file is too big to contain even after compression and so I attach a similar project without compilation.

This project is based on Quartus 15.1 standard edition installed on Linux.

If you compile this project directly using the command below, you are likely to find the error attached above.

aoc -v .aoco (project directory) --board c5soc

I personally also has some finding of the errors and would like to share them here.

The text file that records the whole compilation flow of the project is attached as error_file.txt.

The errors are at line 8008 and 8009.

There are some lines just before the error (line 8005-8007):
Info: kernel clk has period: 404.996
Info: kernel clk has multby: 1 and divby: 454
Info: Using adjusted multby: 404996 and divby: 510112584
Multiplying and dividing numbers in these lines give rise to the overflow and probably this is the reason for the error.
Look at these numbers at the stage just after adjust_plls.tcl being called (Line 7417-7424):
Info: Solved VCO for C 454: 404.059997201 8 1 1362309 4000 20 2 (vco m n k r cp div)
Info: Computed PLL settings: fmax m n k c0 c1 r cp div
Info: Computed PLL values: 0.889999993835 8 1 1362309 454 227 4000 20 2
Info: finfpd 50.0
Info: post-div fvco 404.059997201
Info: true fvco 808.119994402
Info: kernel_fmax 0.889999993835
Info: kernel2x_fmax 1.77999998767
One can see that after pll adjustment, the clock speed is determined to be maximum of 0.89MHz (0.8899999) which is nonsense.
Then look at the VCO period 404.059997201, and the multiplier (n=1) the divider (c0=454), they all occur in the lines before the error.
In order to compensate this 404.996 MHz to be 0.89MHz, the system makes decision: *404996 /510112584.
Since the smallest frequency the PLL can achieve is not even 0.89MHz, these numbers do not make sense at all and thus cause errors in the STA.
Above are my analysis and further investigation fount that the slack at line 7341 compensates the clock frequnecy is -1103.311!!
This is a huge number and that is why the clock frequency is so low!!
However, I am not sure whether my analysis is absolutely correct and also I am not sure why Quartus gives such large slack.
Therefore, I would still kindly ask help if you can help me solve this problem.
Thank you again!
Mingqiang