Blackpill STM32G431CBU6 - 170 MHz / 32k RAM / 128k ROM / 12-bit ADC and DAC,...

[dobsonr741]

Is this CPU made by ST, or is it a chinese replica?

If it really has the math accelerators, floating point, the rich analog (3 opamps, 4 comparators, voltage reference) then I highly doubt it's a replica. Rather factory reject or maybe stolen or auctioned off.

[Doctorandus_P]

Is this CPU made by ST, or is it a chinese replica?

Who knows, but it looks good and works great, so I don't see reason to worry about it.

Just wait until you've been banging your head to the wall and bouncing between the floor and the ceiling for a few days because you can't get some kind of feature of your chip to work, and then find out later that it's some kind of incompatible chip made by some other vendor.

I hear that fake STM32 chips are made with different brand name. So, if it marked with original ST, most of all it's original.

Nope. Take for example the ubiquitous "Blue Pill". Some (5?) years ago they cost around USD 4 and were great. Then the market got swamped by fakes, and prices also dropped to USD1.5 There are some 8 manurefacturers of xxx32F103xxx chips and it became very common to take one of those chips, blacktop it and print an STM part number on it. There is a long thread about these fakes on this forum.

It's why I stopped buying Blue Pills. (and also because it's a very old chip)
It also shows why I like WeAct. WeAct still sells Blue Pills, but they sell different variants.

This one with an STM part number:
https://www.aliexpress.com/item/1005004918334754.html

And another listing where you can choose between GD, APM and CH variants.
https://www.aliexpress.com/item/1005001474741936.html

And as long as they send you what they show in their shop, it's not a fake, but a ... clone? alternative? At least, as long as you get what you buy I'm OK with it, but when I discover a black topped chip and some other part number printed on it, then it's instant negative feedback. I have no tolerance for that. Just having to fiddle with the ID code in makefiles to get it to recognize some other chip is already more bothersome then the price difference is worth.

[iMo]

Rumors say they cannot copy beyond stm32F3xx technology yet (because the F4+ is difficult). So their copies are limited to stm32F1xx and 3xx chips these days.

[dobsonr741]

Got one, this is the chip. Looks authentic.

A code above the manufacturing date (213) is  different: 129R vs OP’s 1A9R

[DavidAlfa]

Fakes have pretty bad marking quality, with low resolution and irregular characters.
When you see that perfectly laser-engraved marking you know it's original.

[prosper]

I bought a couple. They sure seem to look and act real.

They're a dynamite little platform for mixed-signal work, with the math accelerator. Kind of an odd interface though - you twiddle some register bits to set up the operation you want to perform, then you poke and peek data from a register to get it into and out of the device, as opposed to an instruction set extension to the cpu itself. Feels kind of weird to use.

Still, the thing works great for all sorts of analog work. Got mine doing some audio synthesis stuff so far, and I'm curious to see how far I can take it before it hits it's limits, or I hit my skill limit. DSP maths is not my most favourite thing, and I only just passed my math courses back in school by a not-impressive margin.

[Doctorandus_P]

Just today I had a look at the
b-g431b-esc1. It is an ESC ("Electronic speed controller", aka BLDC motor driver for folks outside the hobby RC market) and it also has an STM32G431 It's not exactly cheap as a development board, but as the complete ESC is included, it's price for around EUR30 is very reasonable for a product you can buy in "western" stores. (Or directly from ST?)

I also opened the design files (altium project) in KiCad and discovered this is an 8 layer PCB, and that makes it quite amazing. All the 3D models are also included and it looks "complete" in KiCad's 3D viewer. (I have not matched schematic symbols with PCB footprints, that is still a limitation in the altium importer in KiCad).