Problems in mapping ff to scan_ff in RTL compiler

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somu.atluri

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Hi,

I am trying to synthesize my design using RTL compiler. when i execute the command
synthesize -to_mapped

I got the below error
Warning : Could not find a scan-equivalent cell. [DFT-510]
: Library-cell ’/libraries/tsmc_25/libcells/DFFHQXL’ cannot be scanned.
: A scan-equivalent cell was not found. A potential scan-equivalent library
cell is considered not usable if it has a ’dont_use’ or a ’dont_touch’ attribute
set to ’true’ in the .lib files. In this case, use ’set_attribute preserve false
<scan_libcell>’ and ’set_attribute avoid false <scan_libcell>’ to make the cell
usable. A potential scan-equivalent library cell is excluded if it does not follow
the Scan Cell Requirements described in the ’Library Guide for Encounter RTL
Compiler Ultra’. This requires fixing the library.

I am using libraries from Nangate (45nm). I can see the scanFF in the library files.

I tried some troubleshooting steps from Cadence documentation...
set_attribute preserve false scan_libcells
set_attribute avoid false scan_libcells

I tried this on all the scan cells in the library, but dint help.

Any one faced this issue?? Any ideas/inputs?

Thanks in advance.
 

Guys,

Somebody throw some light on this, I am really stuck with this issue and cant move any further without fixing this.

I am open to use any library (any open libraries available online), suggest me if anyone knows some open libraries.

Also, one issue i would like to highlight, in my libraries i have 3 formarts - CCS, ECSM, NLDM.

I source any of them, I get this error...
Warning : Found CCS construct in the cell. [LBR-408]
: Found 'CCS' construct in file 'NangateOpenCellLibrary_typical_conditional_ecsm.lib', at line 281, column 27.
: Currently, CCS constructs are only parsed & ignored.

Are there any compatibility issues between CCS and RTL Compiler??
 

CCS library is used to do power analysis . RTL compiler accepts ECSM for it. U can convert CCS to ECSM in EDI (encounter) and read it in RC.
But I dont know, why u will ECSM or CCS in RC?.
Are u doing power analysis in RC?
 

I am not doing power analysis in RC, I am just loading the libs and i get this CCS error, even when I load ECSMor NLDM, thats strange.

Added after 9 minutes:

I find these libs in my library. Which one should I be loading. Am I supposed to use the last one - functional?

NangateOpenCellLibrary_typical_conditional_ccs.lib
NangateOpenCellLibrary_low_temp_conditional_ccs.lib
NangateOpenCellLibrary_fast_conditional_ccs.lib
NangateOpenCellLibrary_slow_conditional_ccs.lib
NangateOpenCellLibrary_worst_low_conditional_ccs.lib

NangateOpenCellLibrary_fast_conditional_ecsm.lib
NangateOpenCellLibrary_low_temp_conditional_ecsm.lib
NangateOpenCellLibrary_slow_conditional_ecsm.lib
NangateOpenCellLibrary_typical_conditional_ecsm.lib
NangateOpenCellLibrary_worst_low_conditional_ecsm.lib

NangateOpenCellLibrary_fast_conditional_nldm.lib
NangateOpenCellLibrary_low_temp_conditional_nldm.lib
NangateOpenCellLibrary_slow_conditional_nldm.lib
NangateOpenCellLibrary_typical_conditional_nldm.lib
NangateOpenCellLibrary_worst_low_conditional_nldm.lib

NangateOpenCellLibrary_functional.lib
 

load NLDM in RC.
CCS is synopsys power format
ECSM is cadence power format

Best of luck
 

hi aravind,

thank for the reply. loading NLDM libs dint help.

i still get the same error while loading,

Warning : Found CCS construct in the cell. [LBR-408]
: Found 'CCS' construct in file 'NangateOpenCellLibrary_typical_conditional_nldm.lib', at line 265, column 27.
: Currently, CCS constructs are only parsed & ignored

and when i do the mapping, i get the same error...
Warning : Could not find a scan-equivalent cell. [DFT-510]
: Library-cell '/libraries/NangateOpenCellLibrary/libcells/DFFR_X1' cannot be scanned.

any idea why its showing CCS error when I load NLDM libs?

and is there any way to get rid of the error "currently CCS constructs are only parsed & ignored", i feel thats the reason RC is not able to recognize the scan flops in the library im loading.

thanks a lot again.
 

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