Postprocessing a Magic Design

Cadence and Magic use different file formats for the storage of design data.
Interchange is possible via a common GDS2 stream format.

Procedure

• go to magic directory

    hart<~>$ cd ~/design/fcde/magic/design
  

• translate the top level magic file to cadence format

    hart<~/design/fcde/magic/design>$ do_c035u_desin <topcell>
  

The Magic layout editor supports simple on-line DRC.
The Cadence Virtuso layout editor supports the Mentor Calibre DRC post-processor.

Magic designs must pass the more stringent Calibre DRC before they will be accepted for fabrication.

Procedure

• change to directory containing cadence files

    hart<~/design/fcde/magic/design>$ cd ~/design/fcde/cadence
  

• start cadence

    hart<~/design/fcde/cadence>$ cds
  

• use the library manager for library, cell and cellview manipulation

    Tools -> Library Manager...
  

  within the library browser the left hand mouse button is used for navigating around the library structure while the middle mouse button provides access to the commands used to manipulate the libraries, cells and cellviews.

  • open the imported design for edit

    use the mouse to select Library: fcde, Cell: <topcell> and View: layout then invoke the open command -

      File -> Open...
    

• Run the Calibre DRC

    Calibre -> RUN DRC
  

  in the first of two Calibre windows select the runset file

      Load Runset File
        Runset File Path [ calibre_dir/drc.runset       ]
      OK
  

  from the second Calibre window invoke the DRC

      Calibre Interative - nmDRC
        Run DRC
  

• View the results

  Calibre is very fussy, you will undoubtably have some errors.

  If you select the errors from the Calibre DRC : RVE window, you will get a text description of the error in the bottom pane of the window and information about the location of the error in the right hand pane. More usefully, the Cadence Virtuoso layout window will jump to view the highlighted error.

• While some errors may be rectified by post processing of the designs (e.g. dummy metal generation to overcome "density" problems), others will require you to modify your original magic design

• If performing a DRC on a full design including black box (abstract) pad cells, you will probably have to perform the DRC on the core area only in order to avoid spurious DRC and ERC errors.