Puzzle 20 of 100

An inverter on its side

Goal

Make Y the inverse of A. Here VDD runs down the left edge, GND down the right edge, A enters at the top, and Y leaves at the bottom.

Die: 12 by 12 squares
Layers: Metal, Polysilicon, Contact, N active, P active, N well
Input: A
Output: Y
Supply: VDD
Ground: GND

Go to the solution

Hint

The inverter works in any direction. Turn the usual drawing on its side: the P transistor in a well beside VDD, the N transistor beside GND, and one polysilicon line from A across both.

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 20, An inverter on its side, 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 20, An inverter on its side, 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 20, An inverter on its side, 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

Metal46 squares
Polysilicon11 squares
Contact7 squares
N active5 squares
P active10 squares
N well32 squares
Input padA
Output padY
Supply padVDD
Ground padGND
Squares you draw, change, or erase56 squares

About the drawing

The drawing uses 80 of the die's 144 squares.
Part of the drawing is in place when the puzzle opens. To finish it, paint 56 empty squares.
It forms 2 transistors: 1 N transistor and 1 P transistor. Each one is a place where polysilicon crosses active silicon.
7 contacts join metal to the polysilicon or active silicon under it.

Starting drawing for puzzle 20, An inverter on its side, on a numbered grid. — The drawing when the puzzle opens. The dashed outline marks the squares the solution changes.