Reverse Engineering the Microchip CLB
4 comments
·June 29, 2025throwaway81523
Eduard
only 32 LUTs also made me scratch my head: what kind of useful things can be made with so few components?
Microchip has a web page about "CLB"
https://www.microchip.com/en-us/products/microcontrollers/8-...
It includes a creative demo where your browser apparently gets hooked up with a live video stream of an actual running toy hardware setup of a "CLB demo featuring a European traffic light". It's effectively a finite state machine with two red-yellow-green traffic lights. This minimal setup already consumes 26 of the available 32 units.
Btw: as a European, let me assure you that our intersections usually consist of more than two traffic lights, include a fault state (blinking yellow light), and feature synchronized pedestrian lights on which we mostly stand until they turn green.
indrora
> only 32 LUTs also made me scratch my head: what kind of useful things can be made with so few components?
There's plenty of options: Memory mappers and Very Simple encryption come to mind. Stuff that is intended to make it Just That Much Harder to get to. Very tiny little finite state machines that handle One Thing.
RicoElectrico
> However, they don’t document how to configure it yourself, only referring you to their online configurator tool that submits jobs to an API that places and routes to LUTs.
This is just insane. SaaS-ification got even the largely conservative embedded market.
Nice, but some examples of (potential) applications would be nice Why just 32 LUTs instead of at least a few hundred? Enough to build a specialized SERDES or that sort of thing.