Circuits: VLSI

Puzzle 5 of 100

Crossing paths

Goal

Connect A to Y and B to Z. The two paths must cross without joining.

Die
13 by 9 squares
Layers
Metal, Polysilicon, Contact
Inputs
B, A
Outputs
Y, Z

Go to the solution

New in this puzzle

Two levels

Insulation separates metal from polysilicon, so the two can cross without joining; only a contact joins them. The side view under the die shows the levels of the row under the pointer.

Guide

  1. Paint metal straight across from A to Y.
  2. Paint one square of metal below B and one above Z. Stop there, because metal that touches the A line joins it.
  3. Choose Polysilicon and paint from the end of B's metal to the end of Z's metal, passing under the A line.
  4. Choose Contact and place one on each end of the polysilicon strip, where it meets the metal.

Hint

Metal and polysilicon are separate layers, so a polysilicon strip can pass under a metal line. A contact joins metal to the polysilicon under it. Take B through polysilicon where it crosses the path from A.

Solution

This is the game's reference drawing for the puzzle. It meets the goal and passes the design rules. Other drawings can pass as well.

Top View of the solved die for puzzle 5, Crossing paths, with the Side View below it.
Top View of the solved die, captured from the game. Paths that carry a high level at the moment shown are lit. The Side View below cuts through the row between the dashed lines.
The game window in Isometric View with the solved die for puzzle 5, Crossing paths, the guide, and the scope.
The whole game window in Isometric View. The scope on the right compares each output with its target band, and the message above it confirms that the drawing passes.
Solution drawing for puzzle 5, Crossing paths, drawn on a numbered grid with every layer in its game color and pattern.
The solution on the grid. Squares are numbered from the top left corner, so you can count them.

Legend

  • Metal19 squares
  • Polysilicon5 squares
  • Contact2 squares
  • Input padB, A
  • Output padY, Z

About the drawing

  • The drawing uses 21 of the die's 117 squares.
  • The die starts empty, so you draw every square.
  • 2 contacts join metal to the polysilicon or active silicon under it.