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SW4STM32 and SW4Linux fully supports the STM32MP1 asymmetric multicore Cortex/A7+M4 MPUs

   With System Workbench for Linux, Embedded Linux on the STM32MP1 family of MPUs from ST was never as simple to build and maintain, even for newcomers in the Linux world. And, if you install System Workbench for Linux in System Workbench for STM32 you can seamlessly develop and debug asymmetric applications running partly on Linux, partly on the Cortex-M4.
You can get more information from the ac6-tools website and download (registration required) various documents highlighting:

System Workbench for STM32


You are viewing a reply to [solved] FPU going too slow  

FPU going too slow

Hi Bernard.
Thank you very much for all these clarifications, I understand much better now! I am gonna do some experimentation with moving some parts to RAM and post the results here (if there are any conclusive results).

About the FLASH_ACR register, I should : set DCRST and ICRST, *then* set the 3 bits to enable prefetching?
Last thing, you said that STM32F411 had 0 wait state at any clock frequency (and I’ve read that on the product page as well). That means that 100 MHz IS indeed the best solution to go fast, right? I don’t have to determine the best clock value given that increasing the clocking speed will not induce any more wait state? This leads me to another question : why would someone run the F411 (or other) slower than 100 MHz if it’s 0 wait state at 100 MHz? My first thought was power consumption, it might make a significant difference... Are there any other criterias?

Thanks a lot for your help,

Florent

France

Hi Florent,

Yes the main reason to run slower may be to save power; however if you carefully use WFI (or WFE) for sleeping when you don’t have anything to do (waiting to be woken up by some interrupt, even masked for WFI, only unmasked ones for WFE) then you may achieve about the same power consumption at 100MHz, but have better response times due to the higher CPU frequency.

Of course this is only valid if you are interrupt-driven; if you use polling, you can’t use WFI/WFE and then decreasing teh CPU frequency to what gives you the needed performance will provide you with better battery life.

Bernard (Ac6)