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STM32F746 USB Host examples do not work with vars in SRAM1 ?

Question asked by nikolaou.christos on Aug 31, 2016
Latest reply on Jun 26, 2017 by Gunnar Bohlen
Hi,
Using the CubeF7 USB Host examples ok with default provided linker script (using SW4STM32 SystemWorks IDE).

Yet, when moving the .bss & COMMON section out of the DTCM RAM region into the SRAM1 RAM region, example programs stop working properly their USB functions.
E.g. no enumeration happens etc.
(DTCM = 0x20000000 .. 0x20010000)
(SRAM1 = 0x20010000 .. 0x2004C000)

Is there a caveat or something to know regarding the used variables of USB Host middleware in accordance to memory mapping? Are there any DMA restrictions for that somewhere in USB?
(Similar there are some variables placed specifically in DTCM for the ethernet module in other examples but not in USB Host examples)

If there are some critical variables (like those in ethernet) I could put them specifically in DTCM via linker scripting, yet I need to know which are those.

Any hints are welcome.

Christos

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