Why so many different types of memory on STM32 eval boards?

[barycentric]

234567890-

[andersm]

As the name says, it's an evaluation tool. It allows you to test as many features of the chip as possible. It's not meant to be a module you put into a product.

[SiliconWizard]

Yep. All those memories have a different access bus and different characteristics in terms of latency/throughput. You may need any of them in a particular application, so eval boards just allow you to evaluate that without having to buy/connect anything else.

[ataradov]

Also keep in mind that STM32H7 can't run real Linux.

Usually Linux-based boards actually pick specific memory types and stick with them. There is often "the best kind".

For MCUs the range of applications is wider, so having multiple memory types for evaluation is justified.

[ajb]

One big reason is that LCD, which will need a frame buffer if it's using the built-in TFT interface.  640x480x3 (assuming 24bpp) = ~1MB, before accounting for any double buffering or working memory for images or transformations.  So that alone means you definitely want some extra RAM.  Plus you probably want some stuff to display on it, and the 2MB of built-in flash isn't going to go very far when it comes to storing even compressed images on top of your application requirements.

[ataradov]

Is there an STM32 that can run "real" Linux? I'm aware that most boards can only handle embedded Linux. The H750 is just an example - I can use the F429 or similar in my application with no real performance loss.

I'm not sure, I'm not aware of their MPU line up. But you basically need to look for something based on Cortex-A.

"Embedded Linux" is really not worth it. You will have much better experience with FreeRTOS if you want to go the OS way.

[andersm]

Is there an STM32 that can run "real" Linux?

The STM32MP1 series features dual Cortex-A7 cores.