Library preparation for Design Compiler in topo mode

[rocking_vlsi]

Hi


I want to run Design compiler in topo mode.

1) my first question is how to create milyway reference design?
2) what are the types files, that we can give physical information of cells to design compiler?
3) i have tf file, itf file, lef file, gds fle, mw/target_librayr/CELL, mw/target_library/FRAM? If last CELLand FRAM contains physical information how to read it in design compiler.
4) How to generate DEF file (Floorplan) ?


Please excuse me if it is repeated question.

 

[jrwebsterco]

If not already, you should register with Synopsys' SolvNet support site, and download the "Reference Methodology" (aka RM) scripts package for DC-Topo.
This will have all of the commands already properly scripted for you and you typically only need to change the library names to your specifics.
Using the RM's will also benefit if you later need assistance from Synopsys AEs or tech-support.

These will also serve to answer most your questions via the commands in them to create a MW design library before the design and DEF actually gets read-in and topographical placement-aware synthesis can begin.
The "create_mw_lib" command is effectively what you are asking about in questions (1), (2) and (3).
(do you have access the man-page for that command? But again it is MUCH easier to start from the RM script examples.)
The "set_tlu_plus_files" command will want some of those other files.

DC-Topo only needs the simplified MW FRAM views and the .db (compiled Liberty) technology libraries for the std-cells and all macros.
(the MW CELL views are instead for doing P&R in ICC)

You will need an ICC license (or some other P&R or FP tool) to create a DEF file (even if you do it in DC-Graphical via the ICC-inside-DC feature).
However, you could choose to avoid that by instead using commands like "create_die_area" and "create_terminal" and "set_attribute" (the latter for placing and orienting hard-macros).
(but note this approach is not generally recommended and is inferior to and harder to graphically create and interactively modify than a DEF)

 

[rocking_vlsi]

What will be mw_reference_library in create_mw_lib ?

 

[jrwebsterco]

It's a list of paths to all your MilkyWay reference libraries - the FRAM views that you asked about before.
Every std-cell & macro that is available as a DB via your link_library should correspondingly be available as a FRAM via this variable.

 

[George_P]

Hi,

After checking into the solvnet-RM scripts, it is still unclear to me, how the FRAM views are read into DC. There is no mention at all of "FRAM" within the RM-scripts tarball.

The only thing I can assume is that when reading in the .db file, DC looks for all necessary FRAM files (depending on the macros defined in the .db) within some specified directory. If this is the case it is still unclear which directory that should be.

Do you have any idea about how FRAMs read-in is invoked?

Regards,
George

It's a list of paths to all your MilkyWay reference libraries - the FRAM views that you asked about before.
Every std-cell & macro that is available as a DB via your link_library should correspondingly be available as a FRAM via this variable.

 

[jrwebsterco]

Your assumption is incorrect.
First, make sure you selected "Topo" or "DCT flow" or something like that as an option to the RM-script downloader on SolvNet.
(I don't recall if Topo flow is in the default config for the RM script for DC)

Second, look at file rm_setup/dc_setup.tcl, and search for where the mw_reference_library variable is set.
Notice that the RM script sets this from another variable MW_REFERENCE_LIB_DIRS, which was set earlier in common_setup.tcl.

The key hint here is that this is only creating a list of MW *DIRS*, and not a list of files.
MW libs typically can contain e.g. CEL and FRAM views, and DC already knows implicitly to look under a FRAM/ subdir under the directory paths that you list here.
(if you do not already have FRAM views of your tech libraries, then you are not even ready to do this step and need to talk to your library vendor)

Bottom-line is that you are making a list pointing to all the root-dirs of your various MW libs (std-cells, I/Os, RAMs, etc.), and not to individual files nor to the FRAM sub-dir.
The commands needing this list of directory paths is create_mw_lib and set_mw_lib_reference, which should be obvious from the RM script content.

Finally, note I have not looked at RM-scripts since about v2011, but I doubt any of these details have changed since.

 

[George_P]

Thank you Jrwebsterco,

indeed, what you say is still valid for the latest RM-scripts (2013.03).

Best regards,
George