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Liberate : char_library error

fengye

Hi, everyone,

    I need some help for generating LIb with Liberate. The error reminder include

WARNING (LIB-411): An estimated max load value of 2.98572e-14F will be used for pin: 'Z' of cell: 'INVM0R' because the auto_index algorithm failed to determine the max load using bisection. This can occur when the inside-view algorithm cannot determine a valid vector. Add appropriate 'define_arc' commands specific to pin 'Z' and rerun.

INFO: Write Liberty
LIBERATE parameter "mx_format_expand_buses" set to "0"
LIBERATE parameter "ecsm_multi_stage_cap_mode" set to "0"
LIBERATE parameter "ccsp_mode" set to "0"
LIBERATE parameter "enable_command_history" set to "0"

*Error* (char_library) : Bad ccs data found in #0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 ccs vector for cell:INVM0R, pin:Z, related_pin:A, when:"". This timing group will be skipped!!
*Error* (char_library) : Bad ccs data found in #0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 ccs vector for cell:INVM0R, pin:Z, related_pin:A, when:"". This timing group will be skipped!!

I'm confused that the information show there is no failling cell, but the error information occurs at "Write Liberty"

Characterization statistics:

Number of cells to characterize = 1
Number of define_cell commands = 3
Number of passing cells = 1
Number of failing cells = 0

Could someone give me some suggestions? I'm so grateful.

Parents
  • Guangjun Cao

    Hi Fengye,

    is the NLDM model successfully characterized? please check the waveform of I(Z) and V(Z). Does V(Z) reach full rail?

    Regards,

    Guangjun

  • fengye
    in reply to Guangjun Cao

    Hi Guangjun,

    I use ccs and ecsm model for char_library. The error information means the characterization is sucessful and the lib file is generated. But in the end, the above error information occurs. I don't know how to check the waveform is correct or not

    Regards,

    fengye 

  • Guangjun Cao
    in reply to fengye

    Hi Fengye,

    As I said, check the current and voltage waveform of pin Z. The first thing to check is whether the voltage reach the power/ground.

    I can hardly help without the actual data to play with.

    Guangjun

  • fengye
    in reply to Guangjun Cao

    Hi Guangjun,

        Thanks for your reply! I just find that if I only change the setting of extsim_cmd without any other change, this error don't occur. At first, I use the hspice verison is 2018, now the verison is 2013. So, the problem is the software verison?

     Regards,

  • Guangjun Cao
    in reply to fengye

    Glad you found the cause.

    However, I can not comment on how to use hspice for the characterization, esp. when it is version related. 

    in general, Liberate might not support latest SPICE simulators from other vendors. 

Reply
  • Guangjun Cao
    in reply to fengye

    Glad you found the cause.

    However, I can not comment on how to use hspice for the characterization, esp. when it is version related. 

    in general, Liberate might not support latest SPICE simulators from other vendors. 

Children
  • fengye
    in reply to Guangjun Cao

    Hi Guangjun.

    Thanks a lot ! 

    Regards,

    fengye

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