A dynamic gate followed by an inverter has an output that is low during precharge and can only rise during evaluation. Stages like this can feed each other, and a change passes through them one after another, like a row of falling dominoes.
Hint
The two dynamic gates are joined directly, so the second one can discharge at the start of an evaluation, before the first has had time to fall. Put an inverter between them in the gap. Its output stays low until the first gate falls, so the second gate waits for it.
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, 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 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.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
Metal170 squares
Polysilicon105 squares
Contact40 squares
N active48 squares
P active32 squares
N well104 squares
Input padCLK, A, B, C
Output padY
Supply padVDD
Ground padGND
Squares you draw, change, or erase38 squares
About the drawing
The drawing uses 331 of the die's 558 squares.
Part of the drawing is in place when the puzzle opens. To finish it, paint 29 empty squares, change 8 drawn squares, and erase 1 square.
It forms 12 transistors: 8 N transistors and 4 P transistors. Each one is a place where polysilicon crosses active silicon.
40 contacts join metal to the polysilicon or active silicon under it.
The drawing when the puzzle opens. The dashed outline marks the squares the solution changes.
