+ Post New Thread
Results 1 to 7 of 7
  1. #1
    Member level 2
    Points: 915, Level: 6

    Join Date
    Mar 2014
    Posts
    47
    Helped
    0 / 0
    Points
    915
    Level
    6

    DRC errors in Calibre about three consecutive metal layers and dummy layers

    Hi. I am using TSMC65nm design kit and Calibre for DRC. I am facing two general violations that I would be thankful if anyone can help with. I am doing DRC for a simple fill cell (5 um x 5 um) that contains all the metal layers and vias. There are the errors:

    1. "It is not allowed to have local density > 0.8 of all three consecutive metal layers (M1,M2,M3) over any 50 um x 50 um window". My cell is 5 um x 5 um, so i assume it is less than 0.8 of 50 um x 50 um....

    2. "DM1 is a must. The DM1 CAD layer must be different from M1 CAD layer." I assume DM1 stand for metal 1 dummy layer. I have no idea what a dummy layer is + it is not even among the used layers in the design....

    •   AltAdvertisement

        
       

  2. #2
    Advanced Member level 5
    Points: 8,433, Level: 21

    Join Date
    Apr 2016
    Posts
    1,771
    Helped
    312 / 312
    Points
    8,433
    Level
    21

    Re: DRC errors in Calibre about three consecutive metal layers and dummy layers

    1 - you shouldn't do density checks on IP, makes no sense. use the appropriate flags in the DRC deck to change to IP mode.
    2 - dummy M1 is M1 used for fill. it's standard TSMC nomenclature. This is a drawing layer in virtuoso and has a different datatype than regular M1.



    •   AltAdvertisement

        
       

  3. #3
    Member level 2
    Points: 915, Level: 6

    Join Date
    Mar 2014
    Posts
    47
    Helped
    0 / 0
    Points
    915
    Level
    6

    Re: DRC errors in Calibre about three consecutive metal layers and dummy layers

    Quote Originally Posted by ThisIsNotSam View Post
    1 - you shouldn't do density checks on IP, makes no sense. use the appropriate flags in the DRC deck to change to IP mode.
    2 - dummy M1 is M1 used for fill. it's standard TSMC nomenclature. This is a drawing layer in virtuoso and has a different datatype than regular M1.
    1: Would u plz clarify what you mean by IP?

    2: Do you have an idea how I can get rid of that DRC error?



    •   AltAdvertisement

        
       

  4. #4
    Advanced Member level 5
    Points: 8,433, Level: 21

    Join Date
    Apr 2016
    Posts
    1,771
    Helped
    312 / 312
    Points
    8,433
    Level
    21

    Re: DRC errors in Calibre about three consecutive metal layers and dummy layers

    Quote Originally Posted by dreamyboy_999 View Post
    1: Would u plz clarify what you mean by IP?

    2: Do you have an idea how I can get rid of that DRC error?
    Oh boy.

    Read the documentation that came with the PDK. You are using the wrong DRC deck, and using the wrong layers for fill.



  5. #5
    Member level 2
    Points: 915, Level: 6

    Join Date
    Mar 2014
    Posts
    47
    Helped
    0 / 0
    Points
    915
    Level
    6

    Re: DRC errors in Calibre about three consecutive metal layers and dummy layers

    Quote Originally Posted by ThisIsNotSam View Post
    Oh boy.

    Read the documentation that came with the PDK. You are using the wrong DRC deck, and using the wrong layers for fill.
    That's the fill cell that is provided by the PDK...I am sorry I am new to this PDK, so my questions may seem naive. You think I am using a wrong DRC file (can you please clarify why?)? It looks like it was the one that they provided for Calibre...



    •   AltAdvertisement

        
       

  6. #6
    Advanced Member level 5
    Points: 8,433, Level: 21

    Join Date
    Apr 2016
    Posts
    1,771
    Helped
    312 / 312
    Points
    8,433
    Level
    21

    Re: DRC errors in Calibre about three consecutive metal layers and dummy layers

    Quote Originally Posted by dreamyboy_999 View Post
    That's the fill cell that is provided by the PDK...I am sorry I am new to this PDK, so my questions may seem naive. You think I am using a wrong DRC file (can you please clarify why?)? It looks like it was the one that they provided for Calibre...
    either there are two DRC decks or there is one deck that can be configured. open the calibre deck in a text editor and you will see lots of options that can be turned on/off. refer to the documentation to find out which one switches from IP mode to CHIP mode.

    If this cell really came with the PDK then you don't need to worry about the DM1 error. Again, look at your deck. Most certainly there are switches that you can disable so it will stop checking for fill when fill isn't yet present.


    1 members found this post helpful.

  7. #7
    Member level 2
    Points: 915, Level: 6

    Join Date
    Mar 2014
    Posts
    47
    Helped
    0 / 0
    Points
    915
    Level
    6

    Re: DRC errors in Calibre about three consecutive metal layers and dummy layers

    Quote Originally Posted by ThisIsNotSam View Post
    either there are two DRC decks or there is one deck that can be configured. open the calibre deck in a text editor and you will see lots of options that can be turned on/off. refer to the documentation to find out which one switches from IP mode to CHIP mode.

    If this cell really came with the PDK then you don't need to worry about the DM1 error. Again, look at your deck. Most certainly there are switches that you can disable so it will stop checking for fill when fill isn't yet present.
    Thanks got it! Anyway, I think I will use the automatic filling rather than doing the filling manually by myself.



--[[ ]]--