Is DMA able to access external FLASH in memory mapped mode?

[Javier1]

I am fiddling with a STM32WB5M discovery kit.

This kit includes a QuadSPI external NOR FLASH chip and i need to understand this in order to make early design choices.

 

Could the DMA access that external FLASH memory space?

I didnt try it yet, but my limited understanding of how DMA magic works is telling me it wont work because QSPI is in the way... am i wrong?

is there any way to include external FLASH/RAM thats accessible by DMA?

[Pavel A.]

Hmm. According to that picture, DMA1 and DMA2 are connected to QSPI, but not clear does it mean access to only the registers or to memory mapped area too. Just try it ?

[Javier1]

>>but not clear does it mean access to only the registers or to memory mapped area too

I was wondering the same thing

>>Just try it ?

Thats what im going to do, ill come back with results.

[Javier1]

Nice, a family specific tutorial

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwiJz-T4xr38AhXHUKQEHZdpC2gQFnoECAwQAQ&url=https%3A%2F%2Fwww.st.com%2Fresource%2Fen%2Fproduct_training%2FSTM32WB-Memory-QuadSPI-interface-QUADSPI.pdf&usg=AOvVaw2aBw7M_gMn4NUHrrF4-lad

no idea what xip is, sounds cool 

 

jumping to AN4760

[Javier1 · Accepted solution]

AN4760

[Piranha]

By the way, the STM32WB5MMGH6 is a SoM, not SoC - a system on a module, not a chip.

[Javier1]

@Piranha​ got it

[Piranha]

For a DMA access only to registers would be a terribly useless design... 😉

[Javier1]

@Piranha​ would you care to elaborate?

The specific application would be DMA reading a huge buffer from the external flash and driving a TIM PWM (WS2812B led arrays)

[Piranha]

My post was a response to a post by Pavel. 🙂