How to utilize 4.2MB RAM in STM32N6

[Jayesh2]

Hi,

I am using STM32N6570-DK kit. In my application I need ~3.5MB of RAM but if I allocate more than 256KB of RAM I get the error "region `RAM' overflowed by xxxx bytes". 

I got the same results as well when I imported "UART_HyperTerminal_IT" example for STM32N6 and added 256KB buffer. I got the same error "region `RAM' overflowed by 3328 bytes". I am attaching the same code here for reference.

I thought STM32N6 has 4.2MB of RAM as mentioned in datasheet. How can I fully utilize it? 

[Tesla DeLorean]

Describe distinct memory regions in the Linker Script, and then associate allocations to specific portions via attribute/name on compiler side 

[Jayesh2]

@Tesla DeLorean Thank you for the reply.

After further study I found that I was creating FSBL project which has maximum size capped at 512KB. After that I think I found a right way to develop application. But still I think I can only play with 2048 KB. 

Build "Template_FSBL_XIP" from "STM32Cube\Repository\STM32Cube_FW_N6_V1.0.0\Projects\STM32N6570-DK\Templates" 

I took one dummy array for testing. If I increase the RAM size in "STM32N657XX_XIP.ld" to more than 2048 code does not boot up.

Attaching Template_FSBL_XIP example. Can you please modify the project to utilize maximum RAM?