NeoChrom/GPU2D registers documentation

[robvos]

Will this peripheral ever be documented in detail? i.e. registers, interrupts, etc.

Or even a lightweight/low level library would be acceptable.

We may choose STM32U5 for a product but not if we are forced to use TouchGFX for good performance.

[TDJ]

@DmitryR No doubt new ST MCUs are very strong products. That is why I am still here. However, I start to see a pattern of misleading customers and hiding critical information about product limitations. GPU2D is not the only example. Recently I discovered that USB (OTG_HS) always required external clock or crystal, even when high speed was not used (see this discussion). It is nowhere mentioned in docs but I am quite certain engineering was aware of it. I actually suspected it because NUCLEO-U5A9, unlike other NUCLEO boards, contained two crystals (32.768kHz and 16MHz) - which was not standard. STM32U5xx FDCAN functionality detailed in AN5348 for the large part does not apply to STM32U5xx and it is nowhere clearly stated, especially not in AN5348. On new STM32U5 MCUs FDCAN functionality is substantially limited (details here).
Clearly, software engineering, as a support function generating no income, can hardly follow hardware engineering and marketing. As the result, ST is not a company known for excellent customer support. STM32U5G9 and two boards containing it are already available for purchase (I already received 4 pieces) but still no CubeMX support. I do not even mention HAL quality. Did anyone ever see HAL test suite? Ofc, this question is rhetorical.

[mrrobot]

Hi Gaetan,

Some follow-up questions:

• Why is this documentation being withheld from us?
• Who are these partners?
• When will we have access to their libraries that use the full extents of NeoChrom abilities?

[TDJ]

@mrrobot Best to my knowledge, ST believes that GPU2D is too complex for you (and myself) to handle.
But the true may be that they are still working on docs or MPUs with GPU2D were released prematurely or ST just wanted to give TouchGFX team a head start - who knows for certain? These days not telling customers the truth is a standard business practice.

[DmitryR]

Hi all,

I have mentioned that all other chips from ST use GPUs from VeriSilicon, so it is very likely that U5 uses it too. And those for MCUs from VeriSilicon use VGLite API. It is not at all simple but LVGL implements VGLite starting from version 9.0, so if you play with hardware configuration you may be successful engaging GPU from U5 with LVGL. 

Regards,

Dmitry

[mrrobot]

Based on all the nema_XXX calls & symbols inside the TouchGFX HAL, it looks like this GPU might be from Think SIlicon: https://www.think-silicon.com/nema-gfx-api

It looks like the NemaGFX API matches the headers in what gets put in Middlewares/ST/touchgfx_components/gpu2d/NemaGFX .  I'm having touble finding documentation for the Nema VG extensions, though.

[TDJ]

@DmitryR IC, so probably as long as possible ST wants to maintain impression that GPU2D is ST's invention. It may be another true reason why docs are not released - this is how detached from the reality top mgmt can be.
As a matter of fact, I implemented STM32 DMA2D support for LVGL and was already asked if I could do GPU2D as well but I am still too busy with other projects. Not to mention I truly believe this is something ST could and should engage with although it is clearly against the current ST's philosophy of self-supporting communities providing free product support for badges and kudos and little/no official support but lots of savings. I swear, once TI has comparable product I change vendor. With them it is completely different experience.

[JMYGI · Accepted solution]

Dear Community
We are preparing to share basic documentation, code examples and required NemaGFX libs through NeoChromSDK. The NeoChromSDK comes in versions dedicated to one STM32 series (STM32U5x9, STM32H7R/S) supporting code examples to dedicated STM32 discovery kits.

Main target user of NeoChromSDK is GUI expert wanting to utilize NeoChrom(VG) GPU features, not using TouchGFX or other GUI tools already prepared to utilize the features of NeoChrom GPU.

We are working on a solution to share it through ST.com on a demand approach as it requires expert-level, and support on NeoChrom GPU is not mass market available. The documentation is limited to what is available from the IP vendor Think Silicon. Please note, I recommend using TouchGFX or other tools using NeoChrom GPU if you need dedicated support for NeoChrom features, this is available through the GUI tool vendor, so ST for TouchGFX.

As a temporary solution, you can already contact me on Jorgen.mygind@st.com to request access to NeoChromSDK.

Regards
Jørgen Mygind
STM32 Graphics Business Manager

[DmitryR]

Hello Jørgen,

Thank you very much. I have read the AN5632 and it states that NemaGFX/NemaVG libraries are still precompiled rather than in source code. Because of this your solution will not still be usable for most industrial applications. Please understand that it is not our fancy but in most cases it is simply required to have a source code of the whole application. Otherwise the application appears to be dependent from your support which is in case of large quantity productions is just too risky.

Regards,

Dmitry

[TDJ]

@DmitryR I just ordered evaluation board from another, well-known Dutch vendor with Cortex-M33 MPU using well-documented VGLite GPU2D (LVGL supported). It has much more SRAM than STM32U5G9 and faster clock. I used to be ST-centric engineer but not anymore. Enough is enough

[JMYGI]

Hello DmitryR - I get your point. This limitation is linked to the delivery of Think Silicon, which I do not expect I can change. Though I will mention your strong request to Think Silicon now, If any positive feedback I will share