A chip the size of a fingernail holds a city of switches.
Take the black rectangle out of a phone and it looks like nothing: a flat, dull tile with metal legs. Open it and there is a slice of silicon about a centimetre square. Magnify that slice a hundred times and districts appear — memory here, arithmetic there, a bus running between them like a motorway. A hundred times again and there are streets of wiring. Once more, and you are standing beside a single transistor: one switch, on or off, doing the only thing it knows how to do.
- The package
The black tile is armour and plumbing. The part that computes is the silicon sealed inside it.
- One district
A block like this might be a whole memory array, or one processor core, repeated many times across the die.
- One switch
A voltage on the gate decides whether current may cross. That is the entire trick, repeated twenty billion times.
- 1The package — The black tile is armour and plumbing. The part that computes is the silicon sealed inside it.
- 2One district — A block like this might be a whole memory array, or one processor core, repeated many times across the die.
- 3One switch — A voltage on the gate decides whether current may cross. That is the entire trick, repeated twenty billion times.
Twenty billion one-centimetre tiles make a square about 1.4 kilometres on a side. All of it fits under your fingernail.
Districts, roads, power lines, and rules about what may cross where.
Function blocks, metal wiring, power rails, and gates deciding what may cross where.
Everything a chip does is one switch saying yes or no — twenty billion of them, all at once.