DMA use SRAM???????

[muhammad]

Posted on July 11, 2012 at 14:52

hi all

i need to know that is DMA uses the SRAM as the DMA buffer??????if yes then my MCUstm32F407 got 112Kb and 16Kb of SRAM.and DMA max buffer size is 64kb, in the case DMA is using half of my SRAM,is there a possibility that i can  have shortage of memory in SRAM.if yes then how can i avoid this type of situation........??any help will appreciated a lot....:)  

[Tesla DeLorean]

Posted on July 11, 2012 at 15:03

if yes then how can i avoid this type of situation........??

Use less of it. The 407 also has 64KB of CCM SRAM at 0x10000000, you can use that too, but not for DMA.

[muhammad]

Posted on July 12, 2012 at 12:57

thank you clive1 for your help

just tell, how can i ensure the allocation of my statically declared variables and buffer arrays in C programming, how can i differentiate the memory allocation for DMA and my other uses for variables, while handling crush of data.thank you....:)

[Tesla DeLorean]

Posted on July 12, 2012 at 17:52

Depends on the platform.

If you don't tell the compiler/linker you could floor plan the space manually. Other than that you'd need to specify the memory spaces in a linker script, scatter file, or GUI settings, and then direct the compiler to place specific variables/structures into specific sections. You'd do that with a #pragma, or directive on the allocation, refer to your compiler documentation.