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What are default memory attributes for stm32F4 or other stm32 devices?

mahdi.masoodi1379
Associate II

Hello;

I want implement MPU unit in stm32F4. I have read ST documents about stm32F4xx, but did not find any thing about default attributes (write and read policies) for memory regions before enabling MPU. It means that: what memory attributes dose stm32F4 use in simple project without MPU (as default)?

2 REPLIES 2

0693W000005AggJQAS.png 

It's a simplified version of the generic ARMv7M table, in view of that there's no cache thus that's ignored in the Cortex-M3/4

0693W000005AgffQAC.pngJW

Thank for your answer;

But these above pictures have no hints to "Bufferable" attribute. Also in Cache column, some region have WB attributes which is just about caching capability; but we know that ARMv7-M architecture didn't consider any cache or cache controller inside the processor (outside the processor can be implemented by microcontroller manufacturer), so these attributes can't be considered as default attributes, because some (many) microcontrollers do not have caching capability. In summery there is no any clear description about default attributes. I'm confused!!!

my next question is:

Why, while the ARMv7-M architecture implemented Buffering capability (Bufferable attribute) in the processor, but ST Programing Manual (PM0056) say's that we should program the MPU as the flowing table which dose not consider "Bufferable attribute" for Code and SRAM ? What regions (Code, SRAM, Peripheral and etc.) are bufferable in ARMv7-M architecture? :

0693W000005AhltQAC.pngI would appreciate it if help me. Thank.