guidance for taking forward of custom hw using stm32h743

[jr_engr_mbed]

Hi , As i decided to use h743 lqfp 208 for my application(ECG MACHINE WITH DISPLAY 1080*800-8.88") use of

 

• ETHERNET
• FMC for SDRAM
• QUADSPI
• SDMMC1
• USB OTG FS
• LTDC
• UART, I2C and SPI

is avoiding that h745or747 dual core is ok? 743 is itself enough right?.or is dual core usage is complicated?

As I'm new to PCB design, I initially followed a video for the STM32H723 MCU in an LQFP144 package. However, I later realized that the GPIOs would not be sufficient for my project. Consequently, I found another video featuring the STM32H743 VIT6 in an LQFP100 package, and I decided to replace all the pins from the H723 with those from an H743 in an LQFP208 package. I have some doubts about this approach. Is it correct to swap the GPIOs and make slight corrections to the crystal circuit, VSS, and VDDs by referring to the schematics for the H743 with 100 pins? Or should I follow the reference schematics for the STM32H743 Discovery board, or can I simply follow the video for the H743 in an LQFP100 package?"

 

Mixed-Signal Hardware Design Overview | Audio SoM | STM32 & Altium - Phil's Lab #45 (youtube.com)

Mini 6-Layer Mixed-Signal Hardware Design Walkthrough - Phil's Lab #78 (youtube.com)

[LCE]

I don't know these videos, but in case of doubt I would follow ST's evaluation boards.
Not necessarily when it comes to PCB layout details, because the ST eval boards are built for multiple use cases, which leads to some terribly long signal lines and other issues.

Anyway, read / check / compare datasheets, reference manuals, application notes.

New to PCB design and doing layout for a medical device? Good luck... ;)
Do you have some senior engineers for advice and double checking your work?

 

[jr_engr_mbed]

Thank you for your kind reply. Yes, my role is solely to select the chip and design the schematics, while a senior colleague handles the PCB design. However, he is not familiar with the STM32. Another colleague and I are involved in developing our company's own product using STM32. We have successfully demonstrated this using the F769-DISCO board, and now I need to use an 8.88" display with at least a 1080x800 resolution, so I decided on the H7. Unfortunately, I initially learned schematics from a dedicated H743 100-pin video. As I require SDRAM, LTDC, and eMMC, this would occupy many pins, so I switched to the STM32H743 in a 208 LQFP package instead of the previous one.

As you mentioned, I found a reference schematic for the H753 in the hardware application note. If I follow this reference schematic exactly, will my MCU function properly? Regarding the selection of active components, which should I prioritize? The STM32H753 eval board contains complicated and obsolete parts. What steps should I take after following the basic schematics provided in the reference?

 

 

 

 

 

this is partially followed by ref.. 

[MM..1]

Maybe for you is without SDRAM variant STM32U599/5A9 - STMicroelectronics

If your GUI can use 256 colours only L8 ...

[Pavel A.]

>is avoiding that h745or747 dual core is ok? 743 is itself enough right?.or is dual core usage is complicated?

There are many HMI projects with LCD screen for single core STM32H7 and F7. H743 (in a right package) should be pretty good. The dual core MCUs indeed are more complicated TL;DR and can give you more grief than joy.

 

[Pavel A.]

STM32H753 is exactly same as STM32H743, and has crypto features that may be useful for you.

The only thing to worry about: make sure it is "stepping V", not "stepping Y". The latter is obsolete.

[Pavel A.]

What if you just buy a ready HMI base, such as Riverdi?

[jr_engr_mbed]

 

Hi Pavel, thanks for suggesting Riverdi. Our ECG machine needs a simple GUI, so Riverdi might be too much. Initially, I considered the MP15, as I was forced  with designing a PCB for a patient monitor. Due to time constraints, they told me to do base hardware which is used for both the projects as used like SOM and daughter board, but I'm new here..where I thought for doing hw with single core which is easy for beginners, later I can replace the dusk core h745 MCU alone and draw additional schematic for patient monitor parameters..? After discussing with others in st community, [presently I can do this ECG in h753 and patient monitor in 745] Could you confirm if my understanding is correct?

[Pavel A.]

@jr_engr_mbed Suggestion of Riverdi was exactly because of your time and experience constraints. Other forum patrons have much more expertise in hardware design. I'm a pure software person. 

The display and graphic library are your main concerns - because they define the kind of required external memories (RAM for display buffer and ROM/flash for GUI resources). LCD and the external memories consume a lot of pins.

The other mentioned things - SPIs, UARTs - are trivial. Every STM32 has these and they are quite trivial to handle.

If you can challenge the requirements for the GUI and reduce the display to, say, a monochrome low-res on SPI interface, you can get rid of external memories as well, and use a lower pin count MCU. /* Instead you could compensate by richer functionality: for example, add USB or a wireless interface to talk to a smartphone or cloud service */

[MM..1]

I still mean your idea 1080x800 with SDRAM is on edge of internal vs external bus load. Maybe over edge.

Read LTDC appnote. Next issue is EMI produced with many lines display and sdram. More effective is DSI and internal ram and this all is in new designed series U5. STM32U5G9J-DK2 - Discovery kit with STM32U5G9ZJT6Q MCU - STMicroelectronics

[LCE]

In general: for this project - at least it seems to me - there's no way to keep it really simple.

But it's definitely simpler if you:

a) stay away from dual core

b) in case of doubt, put a little more hardware on the board than might be needed later

For b) I mean especially external RAM:

- FMC with serial RAM is much harder for PCB layout

- QSPI might be not fast enough (I don't know about graphics) 

I recently worked a lot with octal RAM = HyperRAM and OCTOSPI on H735. I use it as data buffer for audio streaming, and it's working absolutely reliable and fast (> 100MB/s) in memory-mapped mode - and that is important to keep it simple. BTW, HyperRAM is relatively cheap.

Unfortunately, some H7s have problems with Quad / Octo SPI in memory-mapped mode, so you better check all info you can get. ST does NOT have a single app note having all the info, I think...