This is the brain of the chip, the thing that knows how to do whatever
it is the GWF wants done.
This is a microcontroller, not a microprocessor. A
microprocessor is what most people think of as the CPU of an
ordinary computer. Strictly speaking microprocessor and CPU are not
interchangeable terms, but the distinction won’t matter here. A modern
microprocessor is billions of transistors/devices. A microprocessor is
much too powerful for the requirements of the chip, and it’s way too
big.
A micro<I>controller</I> is similar to a microprocessor, but it’s much, much simpler, and therefore, can be made much smaller. A microcontroller runs an initialization routine and then runs one program over and over. That’s all that we need for this application. Will a microcontroller fit?
Modern microcontrollers are 32-bit devices; there are 4-bit devices
which would be smaller, but also less powerful.
The smallest microcontroller for which I have a reliable transistor
count dates back to 1974, is a 4-bit microcontroller, and still
contains 8000 transistors. A modern microcontroller will have more.
Even making allowance that this microcontroller will be completely
custom, and even if all of the space is used for the microcontroller,
that’s still only 125 transistors. That’s nowhere near enough.
The microcontroller would have to operate the detector (that can’t see
anything), run the program to report the results (a program that can’t
possibly fit in 2-8 bytes of memory), returning the results (that it
can’t possibly have stored) via an antenna (for which we’ve allowed no
space at all).