Puzzle 54 of 100

A pulse on each rise

Goal

Make Y give a pulse about 6 ns long each time A rises, and stay low the rest of the time.

Die: 42 by 16 squares
Layers: Metal, Polysilicon, Contact, N active, P active, N well
Input: A
Output: Y
Supply: VDD
Ground: GND

New in this puzzle

A pulse from an edge

For a short time after A rises, a delayed and inverted copy of A is still high. An AND gate of A and that copy is high only during that time, so the delay sets the length of the pulse.

Hint

The NAND gate and the inverter after it form an AND gate, with A on one input. Feed the other input from a chain of an odd number of inverters that starts at the line from A, so that it receives the inverse of A, late. The length of the chain sets the length of the pulse.

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 54, A pulse on each rise, 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 54, A pulse on each rise, 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 54, A pulse on each rise, 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

Metal235 squares
Polysilicon92 squares
Contact52 squares
N active23 squares
P active46 squares
N well144 squares
Input padA
Output padY
Supply padVDD
Ground padGND
Squares you draw, change, or erase178 squares

About the drawing

The drawing uses 384 of the die's 672 squares.
Part of the drawing is in place when the puzzle opens. To finish it, paint 176 empty squares and change 2 drawn squares.
It forms 16 transistors: 8 N transistors and 8 P transistors. Each one is a place where polysilicon crosses active silicon.
52 contacts join metal to the polysilicon or active silicon under it.

Starting drawing for puzzle 54, A pulse on each rise, on a numbered grid. — The drawing when the puzzle opens. The dashed outline marks the squares the solution changes.