Shorts and opens

Shorts and opens. LVS (Layout Versus Schematic) checks that the layout connects things exactly as the schematic says. It extracts the connectivity from the drawn metal and compares it to the schematic net list. Two defects break the match:

• A short is metal that joins two different nets, so they read as one. The fix is to remove the metal bridging them.
• An open is a missing connection inside a net, so the net's terminals are not all joined. The fix is to add metal to connect them.

Each pad on the grid is labelled with the net it belongs to. Click a connection (between two pads, horizontal along a row or vertical between rows) to add metal (shown dashed) or remove it (shown solid). Audit every connection: join each net's own pads and keep different nets apart, then Submit layout.

A short can cascade: metal that ties net X to net Y through a pad of net Z merges all three, so one bad bridge can report as several shorts. Adding a connection between different nets creates a short of its own, so connect only what the schematic groups together.