CTS with MMMC

 Hi Sing,

It looks like you may have added too much information when putting in your NONDEFAULT rule. Instead of editing the LEF by hand, try adding your new NONDEFAULT rule using the GUI. (Back your changes out of the LEF first.)

Edit->Object->Non Default Rules...

A form will come up where you can start with the default rule and then change the width and spacing to what you want.Let us know now this works for you!

- Kari

 Hi Kari,

Thank you very for the reply, after looking at the log files, I found the previous error was due to lef files (U are correct in ur reply). I now have the following prbs. 

 1) I want 2 use both SVT and LVT cells in my design, so I am giing both SVT nd LVT .libs and lef file.  Only during CTS the tool crashed complaining abt the spacing table for various layer (as shwn in my 1st mail.) But wen i use only LVT less the design passes CTS. .... any solution so t  hat I can give both lef files. i actually want to use only svt cells for CTS and the rest of teh whole design in LVT.

2) if I use NONDEFAULRULE file along woth shielding, the result post CTS has not shileding, in the log it says,

Options:  -maxRouteLayer 5 -handlePreroute -noKeepMarkedOptRoutes -noPinGuide

Shielding wires of net XXXXX will be removed.
Shielding wires of net YYYY will be removed.

Can u please suggest wht can I do to have shieding, 2x width 2X spacing and use include double via ... all this only for CTS.

SING 

 Hi Sing,

For issue #1, it sounds like you have the lef tech info in more than one lef file. The tech information should only be read in once. Usually, there is a separate tech.lef that is read in first, followed by the std cell lefs, rams, ios, etc. So make sure you are only reading in the tech info once at the very beginning (the tech info consists of the layer difinitions, via definitions, nondefault rules, etc. - pretty much everything except the MACRO definitions).

For issue #2, how are you telling CTS to shield the clocks?

- Kari

Hi Kari

Thanks a lot for the reply. I have no probs with LEF(followed ur reply) . After routing I can see in the layout many of the clock nets are routed with Shielding, but not all the clock nets, I think its because there are no  neighbouring nets for XTalk effect so only the nets with possible Xtalk are shielded with VSS.

most of my problems are solved now. I wll come back if thre are any moer.

Sing 

 Hi Sing,

Glad you got your LEFs working! I'm kind of surprised that you're not getting shielding where there is apparently room, but maybe there is some other reason that nanoroute can't shield the clocks in those areas.

- Kari

Dear Kari, 

Post Route design, I have 2X width and shielding. In order to solve the timing issues I tried to add a repeater like

ecoaddrepeater and the tool crashes. I tried adding first for clock path nd then to signal path but in both cases the tool crashes.any specific reason . or is it a known problem

 Suresh 

 Hi Suresh,

 I wouldn't recommend ecoAddRepeater for the clock tree. If there is something you don't like about your clock tree, you should either refine your CTS spec file and regenerate the clocks, or use ckEco. As for the signal path, I'm assuming you've already tried optDesign -postRoute? Basically, you need to figure out what is causing your timing violations. It may or may not be the clock tree. It's hard to give any more specific advice without knowing more about the timing violations. You can also try the Global Timing Debugger. It's very useful to quickly see what may be causing the problem. See the "Debugging Timing Results" chapter in the Encounter User Guide for more information on this.

- Kari

Dear Kari

 Thank you for reply, its correct not add ecorepeaters to clock path. I tried all the post route opt options and since my design very small and the main objective is speed. I have no much options left else for adding buffers  to clock path. It worked perfectly fine before 2X width and shielding but now it crashes. 

One more question the tool crashes if I add a repeater to data path also which is not normal. Any reasons ?

SING 

 Hi Sing,

The tool should never crash. If the crash is repeatable, please file a service request through Sourcelink. R&D will need a testcase from you to figure out what's happening.

- Kari