Circuits: VLSI

Puzzle 7 of 100

Wires take time

Goal

Make Y follow A about 6 ns late, as the target shows.

Die
14 by 9 squares
Layers
Metal, Polysilicon, Contact
Input
A
Output
Y

Go to the solution

New in this puzzle

Delay

Resistance slows the charging of whatever a wire drives, so the output of a long polysilicon path follows its input late.

Hint

A long polysilicon path charges the output slowly. Fold the strip back and forth to fit about 40 squares between the two contacts.

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 7, Wires take time, 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 7, Wires take time, 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 7, Wires take time, 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

  • Metal4 squares
  • Polysilicon44 squares
  • Contact2 squares
  • Input padA
  • Output padY

About the drawing

  • The drawing uses 46 of the die's 126 squares.
  • The die starts empty, so you draw every square.
  • 2 contacts join metal to the polysilicon or active silicon under it.