Puzzle 62 of 100

Faster than polysilicon

Goal

Connect A to Y across the two wide rails. Y drives a large load and must follow A as closely as the target.

Die: 21 by 5 squares
Layers: Metal, Polysilicon, Contact, Metal 2, Via
Input: A
Output: Y
Supply: VDD
Ground: GND

New in this puzzle

A crossing without delay

Metal 2 resists as little as metal, so a crossing on metal 2 adds almost no delay, however long it is. A polysilicon bridge resists in proportion to its length.

Hint

A polysilicon bridge under both rails is long, and its resistance delays the large load even when the bridge is as wide as the die. Cross on metal 2 instead, with a via at each end.

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 62, Faster than polysilicon, 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 62, Faster than polysilicon, 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 62, Faster than polysilicon, 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. The dashed outline marks the squares you draw, change, or erase; the rest is drawn when the puzzle opens.

Legend

Metal74 squares
Metal 219 squares
Via2 squares
Input padA
Output padY
Supply padVDD
Ground padGND
Squares you draw, change, or erase19 squares

About the drawing

The drawing uses 77 of the die's 105 squares.
Part of the drawing is in place when the puzzle opens. To finish it, paint 5 empty squares and change 14 drawn squares.
2 vias join metal 2 to the metal under it.

Starting drawing for puzzle 62, Faster than polysilicon, on a numbered grid. — The drawing when the puzzle opens. The dashed outline marks the squares the solution changes.