SDF error (encounter to primetime)

[ifforums]

Hi,


I extracted a sdf file from encounter (after place&route step). However, when I wanna feed it into the primetime (using this command: read_sdf circuit.sdf) to extract the delay it gives some errors/warning such as:



Information: Merging of parallel arcs is disabled by read_sdf. (SDF-040)
Warning: The SDF file is version 3.0. Current SDF-3.0
supported constructs are: REMOVAL, RECREM, RETAIN and CONDELSE. (SDF-026)
In timing spec
Error: No net timing arc from pin 'InstQueueRd_Addr_reg_2_/Q' to pin 'U4212/A2'. (PTE-014)
Error: No net timing arc from pin 'InstQueueRd_Addr_reg_2_/Q' to pin 'U6806/A2'. (PTE-014)
Error: No net timing arc from pin 'InstQueueRd_Addr_reg_2_/Q' to pin 'U6826/A1'. (PTE-014)
Error: No net timing arc from pin 'InstQueueRd_Addr_reg_2_/Q' to pin 'U6843/A'. (PTE-014)

Error: No net timing arc from pin 'U2214/ZN' to pin 'U1903/A2'. (PTE-014)
Note - message 'PTE-014' default limit (100) exceeded. Remainder will be suppressed.
Error: Error in SDF file /home/firouzi/benchmarks-synthesis/ITC/b15.sdf Line 17956: Syntax Error at or near token ''. (SDF-008)


Suppressed Messages Summary:
Id Severity Occurrences Suppressed
-------------------------------------------------------------------------------
PTE-014 Error 897 797
Total 1 type of message is suppressed

Thank you for using pt_shell!
[victor@bcom]$ Information: Merging of parallel arcs is disabled by read_sdf. (SDF-040)
-bash: syntax error near unexpected token `('
[victor@bcom]$ Warning: The SDF file is version 3.0. Current SDF-3.0
-bash: Warning:: command not found
[victor@bcom]$ supported constructs are: REMOVAL, RECREM, RETAIN and CONDELSE. (SDF-026)
-bash: syntax error near unexpected token `('
[victor@bcom]$ In timing spec
-bash: In: command not found
[victor@bcom]$ Error: No net timing arc from pin 'InstQueueRd_Addr_reg_2_/Q' to pin 'U4212/A2'. (PTE-014)
-bash: syntax error near unexpected token `('
[victor@bcom]$ Error: No net timing arc from pin 'InstQueueRd_Addr_reg_2_/Q' to pin 'U6806/A2'. (PTE-014)
-bash: syntax error near unexpected token `('
[victor@bcom]$ Error: No net timing arc from pin 'InstQueueRd_Addr_reg_2_/Q' to pin 'U6826/A1'. (PTE-014)
-bash: syntax error near unexpected token `('
[victor@bcom]$ Error: No net timing arc from pin 'InstQueueRd_Addr_reg_2_/Q' to pin 'U6843/A'. (PTE-014)
-bash: syntax error near unexpe

Any idea about it?

Thanks
Regards,

V.

 

[jrwebsterco]

The only idea would be that there is a structural mismatch between the SDF and the netlist you had read-into PT.
The message indicates that the netlist does not have a direct connection between the two cell-pins it mentions.

Have you tried to ...
-> Pull the netlist into an editor ...
-> Pull the SDF into an editor ...
-> And then *manually* cross-reference the offending net-delay statements (in the INTERCONNECT section of SDF) against the netlist details for the arcs they describe?
(e.g. including the need to traverse through the netlist hierarchy as needed, but this looks like a flat netlist)

This would confirm that indeed there is a consistency mismatch between the two files.
Are you certain that you are not e.g. using an SDF or netlist that may have been for a different step in Encounter?
(e.g. before a final DRC-fixing optimization step, which could insert new cells)

BTW, it is impossible to know what that syntax-error is about without seeing the line it refers to.
(Also, you appear to be seeing some odd bash shell-script errors, but maybe is due to improper coding of your run-script.)

Finally, note that typical modern approach is to not read SDF into PT, but instead to read SPEF or DSPF, since that will annotate caps and resistances using RC-network details so that an "official" static-timing-signoff tool like PT can be the one who performs all of the e.g. Arnoldi delay calculations and so on.
(plus reading in the caps also lets PT check max-tran/max-cap DRC violations without having to read-in a second script of set_load/set_res commands)
But it is also possible that your cell-library/silicon vendor might *require* you to use an SDF using their prescribed tool/flow.

 

[itsmeteja]

Please check whether you are exporting the empty modules, (if yes, remove the empty modules).

PT requires that the INTERCONNECT delay for a net in the SDF be between a leaf cell pin and another leaf cell pin, such that a valid driver and load pin combination exist. When it encounters a net which is driven by a hierarchical pin of an empty module, it cannot identify this pin as a valid driver or the start point of a timing net arc (the same applies when the net fans out to pin on an empty module).