Why can't I use all SRAMs?

[ExtSol]

STM32F407VGT6 -> this controller have 192kb of sram, I create a big byte array have 131832 byte and i got an error in Keil.

Any idea why?

[Andreas Bolsch · Accepted solution]

Datasheet "Figure 18. STM32F40x memory map": The SRAM consists of three blocks, non-contiguos ...

[ExtSol]

So, what happend when i switch on IRAM2?

If IRAM2 is off, i cant use all of 128k sram.

[Tesla DeLorean]

You're allocating more than 128KB, and you also have the stack, heap and other variables fighting for the same space.

You should perhaps be using a Scatter File, and defining what goes into the 0x10000000 [64KB] CCM region, like the heap, stack, etc.