The following commands return the same cells in my design:

   get_cells -touching {50 50 100 100}
   get_cells -within {50 50 100 100}

What is the difference between the -touching, -within and -intersect options of the get_cells command?

Answer:

When used with the get_cells command,

• The -within option returns the cells that are totally inside the specified region and do not overlap the boundary
• The -touching option returns the cells that are inside the the specified region, including cells that overlap the boundary
• The -intersect option returns the cells that have common points with the specified region and at least part of the cell boundary is outside the specified region.

The following example shows the difference between these options.

icc_shell> get_cells -within {400 400 800 750}
{U1}
icc_shell> get_cells -touching {400 400 800 750}
{U1 U2}
icc_shell> get_cells -intersect {400 400 800 750}
{U3 U4}
icc_shell> get_cells -intersect {830 70  880 140}
{Mem1}

Note that these options are supported by many of the get_* commands and behave in a similar manner when used with these commands.