Your IDEAL MCU for HMI-of-Things and GFX applications at very low cost !!! The NEW STM32L4+ product is born 😉

[Raouf]

Hello,

The NEW STM32L4P5xx/L4Q5xx devices comes to complete the STM32L4+ Series portfolio.

The new STM32L4+ offers a large package offer from 48 to 169-pin packages with several options.

-         The STM32L4P5 with 512 Kbytes to 1 Mbytes of Flash memory coming with packages supporting external SMPS.

-         The STM32L4Q5 with 1 Mbytes of Flash memory coming with encryption accelerator engine (AES, HASH and PKA).

NEW features

The new STM32L4+ brings several new innovative features. It comes with newer OctoSPI interface enabling to connect Octal flash and PSRAM memories and HyperBusTM memories as well.

OctoSPI: Connecting 2 Octal SPI memories using only one physical interface

Thanks to its new multiplexed mode, it enables connecting 2 Octal memories using only one physical interface.

 

ST is Accelerating the “HMI of Things�? revolution !!!

•In the context of accelerating the “HMI of things�? revolution: ST offers an extended ecosystem enabling HMI of Things

• GFX peripherals: (DMA2D, LTDC, …)
• External memory controllers (FMC, QuadSPI, OctoSPI)
• MCUs with Good Balance of high-performance and power efficiency (like the STM32L4+ Series)
• SW solutions enabling to develop richer GFX (STM32CubeFW, TouchGFX, ….) 

Basic HMI on Small 48-pins packages (Optimized BOM)

•      Only MCU + Display: Ideal MCU for Basic HMI applications with a small low cost packages

•      ALL inside a small device : CPU, Display driver, 2D Accelerator, GFX RAM, Flash, and others….

•      LTDC RGB222 configuration available on ALL packages

•      CLUT L8 color format

•      Single or double buffer ( 240x240 8-bpp)

=> No need for External memories

=> No need for external Display controller

More advanced HMI + Audio + UART+ Others

•HMI (LTDC+OctoSPI) + Audio + Sensors + UART + 10_spare_pins

•When internal RAM/Flash is not enough

•LTDC RGB222 configuration available on ALL packages

•2 External Octal SPI memories thanks to the multiplexed mode

•HyperFLASH

•HyperRAM

•Audio Codec over SAI

•I2C for Display, sensors and Audio Codec

•UART

•10 spare pins

HMI + Audio + Camera + Connectivity + Others

•HMI (LTDC+OctoSPI) + Audio + Camera + Wi-Fi + Sensors + LPUART + 2x SPI + 10_spare_pins

•Thanks to following features availability on LQFP64 package

1. LTDC RGB222 configuration available on ALL packages
2. 2 External Octal SPI memories thanks to the multiplexed mode
3. Audio Codec over SAI
4. Camera over DCMI 8-bits
5. Wi-Fi module through SDIO 1-bit
6. I2C for Display, sensors and Audio Codec
7. LPUART
8. 2xSPI or USB_OTG_FS …
9. 10 spare pins

[waclawek.jan]

Hi @Raouf​ ,

Thanks. The chips are nice, but, you know, it would really increase the atractiveness of this place (I mean the forum), if you would post this sort of information in advance of the official announcement, not after it, making this place somewhat elite.

We are of course already aware of this new addition to the 'L4+ family, and also of the IMO not-that-great DISCO accompanying it - you might want to comment on this.

Also, you present above RGB222 mode, yet there's no official explanation etc. - this ought to be dealt with in detail in an AN, IMO.

JW

@Camilo LEMOS​  @brk​ 

[Raouf]

Hi Jan,

Thank you !!

So good to see people interested :smiling_face_with_smiling_eyes: and I agree with you about the late post ! But I hope it does help discovering the new amazing features on that new product.

With a low cost package (LQFP48 or QFN48) you can build your Graphic application, thanks to the GFX peripherals availability on such small package and also thanks to the new innovative Octal SPI feature named multiplexed mode. On that small package you don't need an external TFT driver thanks to the LTDC, and you don't need to add an external RAM for GFX framebuffer and ext flash for bitmaps thanks to the internal 1MByte of flash and internal 320Kbyte of RAM. But if your application requires more RAM and more flash, no matter thanks to the 2x Octal SPI interfaces, you can connect 2 different octal memories through the same data lines thanks to the multiplexed mode. One memory can be a flash (or HyperFlash) for bitmaps and the other can be an HyperRAM (or SRAM or PSRAM) for Graphic framebuffer.

The RGB222 is a reduced bus for the LTDC interface used to transfer pixels to the display. (2 lines for Red, 2 for Green and 2 for Blue) instead of using the full RGB888. For this mode of 6bits-per-pixel you get 64 colors in display which is quite enough for most HMI appliances. This configuration reduces considerabely the PCB design complexity, the cost and the used GPIOs especially for reduced pin packages.

Of course RGB888 and others (RGB565 or RGB666) are still available on greater packages like the BGA169.

You can also discover the other Application use cases which are available on higher pin packages like the LQFP64 and others. You can also use STM32CubeMX to easily discover and check other configurations...

I hope that helps you ! Don't hesitate to ask more questions..

I will check your question related to Discovery....

Thanks & Regards,

RBEN

[gregstm]

Excellent. The LQFP48 is my much preferred package - especially now that it has 320K of RAM.

[gregstm]

... just a greedy thought. The only other extra thing that I could wish for is an FMAC variant of these chips (in LQFP48 of course). I don't use a lot of graphics but I do use lots of IIR filters in my audio processing and effects. I haven't used the FMAC yet, and I'm still studying/understanding it, but it looks very promising - and now that there is 320K of RAM I can even venture into audio "looping" effects.

[Zaher]

WOW! HMI + Audio + Camera + Connectivity in an LQFP48 package? Even an LQFP64 is not a big investment for most low-cost products!

Over and over again, this proves why the best thing I've done years ago was moving to ST. HMI of things and bringing GFX to embedded designers was one of the best initiatives ST made over the years!

Thank you guys and keep going!

Zaher

[Ikiss.1]

Nice, will any of those mentioned MCUs would work with my display, or i have to use additional SSD1963 ?

Please see attached datasheet for this 5" CTP

My end goal is to design in TouchGFX

[Raouf]

Hi Ikiss,

The L4+ MCU embeds a TFT driver (LTDC) so it is able to drive LCD-TFT displays with resolutions up to 480x480 for a 16bpp (when an external 16-bit SRAM or Octal SPI PSRAM is used as framebuffer) .

Would you please precise the required refresh rate and the color depth (RGB888 ?) ?

For such display resolution I recommend STM32F4x9, STM32F769, STM32H7 ...

And of course you can use TouchGFX for STM32L4+, F4x9, F7, H7 and so on...

The application note AN4861 would be a very good guide for you to properly consider the best HW architecture (system speed HCLK, external framebuffer, ...) and there is a step-by-step guide with STM32CubeMX showing how to properly configure LTDC and display an image...

Thanks & Regards

[Ikiss.1]

Thank you so much, as you can see it on the data sheet i provided, i have a screen that 800x480 24bit RGB.

what is your recommendation for that model ?

Thank you

[Raouf]

Yes, I've already checked the display spec and I asked the question about the the required refresh rate and the color depth RGB888.

I understand that the color depth should be RGB888, but note that you still can use lower bpp like RGB565, this is to save memory and framebuffer bandwidth.

But what about the refresh rate ? Note: refresh rate is the number of framebuffer updates per second

But I want to highlight that for this display resolution 800x480 24bit RGB I recommend STM32F4x9, STM32F769, STM32H7 since the STM32L4+ is limited to 480x480

Best Regards

[Ikiss.1]

I see, 60Hz recommended refresh rate,

[Raouf]

Yes, 60Hz is the display refresh rate, even if you only show a static image.

The framebuffer refresh rate can be up to 60fps if your display is @60Hz.

so depending on your GFX application requirements, you should use the proper fps.

For instance if it is a HMI, 30fps would be enough.

Note that the higher fps, the better is the display visual effect, but also the more your system is stressed (mainly framebuffer bandwidth)