GD32F103RBT6 – the STM32 pin to pin compatible Chinese MCUs sample test


Our previous blog post made lot of buzz about the STM32 pin to pin and functional compatible processors made by Chinese company Giga Device.

Some people at Giga Device got upset from the comments that they probably did STM32 cloning or do not pay ARM licensees and we received this letter from GD32 product family manager Eric Jin:

1. All the products provided by GigaDevice were developed by GigaDevice independently, and GigaDevice has its all intellectual property rights. As the third-party intellectual property rights, GigaDevice has obtained the intellectual property rights holder’s authorization.

2. All the products provided by GigaDevice do not infringe any third-party intellectual property rights.

3. It’s sure that for the record, GigaDevice are a legitimate ARM licensee :

4. And GigaDevice is officially the ARM connected community member and the ARM university programme partner.

5. GigaDevice GD32 series of MCU got the trade mark in world wide such as US, Korea& Japan

6. The right of layout-designs of integrated circuits design of GD32 MCU is protected in China.
GigaDevice also have lots of US,EUROPEAN & INT’L PATENT concerning GD32 MCUs, examples check the attached patent file.




4 PCT/CN2015/071990 PCT International MCU

5 PCT/CN2015/071983 PCT International MCU

6 PCT/CN2015/071556 PCT International MCU

7. We also provide the “Intellectual Property Rights Guarantee letter” and the “Trademark Certificate” for your reference.

8. We will continue to highlight the advantage of our own in market, especially the family roadmap.


We got some free samples of GD32F103RBT6 and replaced the MCUs on STM32-P103, STM32-H103 and OLIMEXINO-STM32. To our surprise these boards pass all functional tests without any modifications, i.e. all the development tools, JTAGs, etc work with GD32 like they are STM32! Also all software code made for STM32 run the same way on GD32 devices, so you can re-use all STM32 code and libraries for these new devices.

How this will affect ST? I don’t know, but I guess not much. Big customers who make probably major share from the STM32 sales already have good prices directly from ST and will not move to something unknown which cost a little bit less.

The prices of GD32F103RBT6 in China are about 20% less than the price you can buy there original STM32 chips. If I was big company I wouldn’t move away from ST as GD32 devices have some claims for higher speed etc, but their web site is total mess and you hardly can find even simple datasheet, not to say that GD32 have no Errata, which is alert for us, in novadays device with no published errata usually means the manufacturer of this device is either hiding something either didn’t test it’s device well enough :). For  big projects switching to noname Chinese supplier is no go as the risks are huge.

For the small customers it’s another story. If Giga device can find reliable small distributors which to stock and sell their products in Europe they will have no competition by ST which use the old fat distribution channels left in Europe which charge for small quantities x3 the prices which is for big customers and obstracle competetive small scale production here.


7 Comments (+add yours?)

  1. cnxsoft
    Dec 21, 2015 @ 12:16:31

    Will you provide a GD32 version of the boards, or did you just test for fun? 🙂


    • OLIMEX Ltd
      Dec 21, 2015 @ 13:16:08

      still hesitate 🙂 it was interesting to see how the replacement work, but as I wrote above vendor who do not publish Errata for his chips is not trustworthy


  2. Trackback: GigaDevice GD32 is a Faster, Software and Pin-to-pin STM32 Compatible Cortex M3 MCU
  3. Maciek
    Dec 21, 2015 @ 21:35:45

    I’d suggest to test GD32 in areas where STM32 fails, e.g. PLL.


  4. LinuxUser
    Dec 25, 2015 @ 16:44:52

    Have you checked if flash write works the same way as in STM32? I mean flash write from STM32 firmware itself.

    Interesting part is: when you run code from flash memory and trying to write something to same flash bank, it gets inaccessible for a while, while erase or program operation progressing. This means one fancy thing: CPU can’t read further code properly. That’s where things are getting interesting. STM32 uses some quite a smartass tricks to deal with it, thanks to the fact their flash controller and memory are tightly integrated, so they manage to sequence bus stuff in the way CPU just halts while flash erase or write is in progress (one can also use faster “burst” page programming, but in this case code MUST NOT run from flash, one can use RAM for flash writer, etc).

    Since this IC is told to have external flash IC, it means flash is not as tightly integrated. That’s where I’m getting curious. I wonder if STM32 code running from flash is going to crash on trying to write flash memory. Or have they learned dark arts of system magic so well they manage to handle it properly? If they did, I would consider their mumblings about IP and somesuch aren’t just loud words.


  5. grombeestje
    Jul 16, 2017 @ 01:15:46

    Looking at their downloads “AN004 Silicon limitations” (2015-03-05)
    Looks like they have published errata after all


  6. Carsten
    Jul 08, 2021 @ 17:27:19

    Are there any updates/experiences regarding replacements? Any concerns to do?


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