Getting the main hierarchy from a multi-topcell design.

Discussion created by yijun_tong on Oct 8, 2009

Some layout designs, usually those came from a merged database with standard cell library, has the following structure.  Un-referenced cells create multiple topcell.  Since they are not used anyway, it would be a good to retrieve only the main hierarchy to get rid of the un-referenced cell.



To clean up lib3 and cells like it, you can try the following script.


set layHdl [layout create layout.gds]
set top [$layHdl topcell]
set tops [$layHdl topcell all]
foreach cell $tops {
  if {$cell != $top } {
    # puts "find $cell"
    $layHdl delete cell $cell


For more explanation of the script, please log on to supportNet and check DESIGNrev reference manual.