To compare two cells, use these commands (in menu Tool / NCC):

- Schematic and Layout Views of Cell in Current Window Use a heuristic to figure out what to compare against the cell in the current window. If the current cell is a schematic then compare it against some layout cell in the same cell group. If the current cell is a layout then compare it against some schematic cell in the same cell group. Since most cell groups have one layout cell and one schematic cell, this form of the NCC command is usually the most convenient.
- Cells from Two Windows Compare the two cells that are displayed in the two opened windows (there must be exactly two windows). This is useful when the schematic and layout are not in the same cell group. The command can also be used to compare schematics with schematics or layout with layout. However, the command refuses to compare icon cells since icons cells don't have defined connectivity.