I have 3 errors and I don't know what is the problem . I use Stm32h755ZIQ with 1MB of Ram and 2MB of Flash .

[STork.1]

[Peter BENSCH]

Not much information is visible on the screenshot you provided. Please select tab Problems in the bottom part of the window to get more information regarding the errors.

[STork.1]

Thanks for your feedback, in the screenshot below the problems are shown but I wonder because the available RAM size for user according to the data-sheet of the MCU is 1MB and more than 800MB are available for user. those global variables I defined just take up 450 MB space . for my application, it is critical to store all data-samples in Ram first, then send them to a WiFi module then clear the buffer to do it again once each hour.

[Tesla DeLorean]

You're going to have to look at the Linker Scripts (.LD). The RAM is NOT all contiguous, you might have to make decisions about which to use based on speed and distance from the core, and how critical any particular data structure is.

Not going to be able to tell what is going on from the screen shot

Thanks for your feedback, in the screenshot below the problems are shown but I wonder because the available RAM size for user according to the data-sheet of the MCU is 1MB and more than 800MB are available for user. those global variables I defined just take up 450 MB space . for my application, it is critical to store all data-samples in Ram first, then send them to a WiFi module then clear the buffer to do it again once each hour.

800/450 MB ??

[STork.1]

I checked the .ld file or the linker script. Since My code is generated by the STM32 Cube MX, my file is named STM32H755ZITX_RAM.ld.

Here is the content of the file:

/*

******************************************************************************

**

** File    : LinkerScript.ld

**

**

** Abstract  : Linker script for STM32H7 series

**        256Kbytes RAM_EXEC and 256Kbytes RAM

**

**        Set heap size, stack size and stack location according

**        to application requirements.

**

**        Set memory bank area and size if external memory is used.

**

** Target   : STMicroelectronics STM32

**

** Distribution: The file is distributed as is, without any warranty

**        of any kind.

**

*****************************************************************************

** @attention

**

** Copyright (c) 2019 STMicroelectronics.

** All rights reserved.

**

** This software component is licensed by ST under BSD 3-Clause license,

** the "License"; You may not use this file except in compliance with the

** License. You may obtain a copy of the License at:

**            opensource.org/licenses/BSD-3-Clause

**

****************************************************************************

*/

/* Entry Point */

ENTRY(Reset_Handler)

/* Highest address of the user mode stack */

_estack = 0x24080000;  /* end of RAM */

/* Generate a link error if heap and stack don't fit into RAM */

_Min_Heap_Size = 0x200 ;   /* required amount of heap */

_Min_Stack_Size = 0x400 ; /* required amount of stack */

/* Specify the memory areas */

MEMORY

{

RAM_EXEC (rx)   : ORIGIN = 0x24000000, LENGTH = 256K

RAM (xrw)   : ORIGIN = 0x24040000, LENGTH = 256K

}

/* Define output sections */

SECTIONS

{

 /* The startup code goes first into RAM_EXEC */

 .isr_vector :

 {

  . = ALIGN(4);

  KEEP(*(.isr_vector)) /* Startup code */

  . = ALIGN(4);

 } >RAM_EXEC

 /* The program code and other data goes into RAM_EXEC */

 .text :

 {

  . = ALIGN(4);

  *(.text)      /* .text sections (code) */

  *(.text*)     /* .text* sections (code) */

  *(.glue_7)     /* glue arm to thumb code */

  *(.glue_7t)    /* glue thumb to arm code */

  *(.eh_frame)

  KEEP (*(.init))

  KEEP (*(.fini))

  . = ALIGN(4);

  _etext = .;    /* define a global symbols at end of code */

 } >RAM_EXEC

 /* Constant data goes into RAM_EXEC */

 .rodata :

 {

  . = ALIGN(4);

  *(.rodata)     /* .rodata sections (constants, strings, etc.) */

  *(.rodata*)    /* .rodata* sections (constants, strings, etc.) */

  . = ALIGN(4);

 } >RAM_EXEC

 .ARM.extab  : { *(.ARM.extab* .gnu.linkonce.armextab.*) } >RAM_EXEC

 .ARM : {

  __exidx_start = .;

  *(.ARM.exidx*)

  __exidx_end = .;

 } >RAM_EXEC

 .preinit_array   :

 {

  PROVIDE_HIDDEN (__preinit_array_start = .);

  KEEP (*(.preinit_array*))

  PROVIDE_HIDDEN (__preinit_array_end = .);

 } >RAM_EXEC

 .init_array :

 {

  PROVIDE_HIDDEN (__init_array_start = .);

  KEEP (*(SORT(.init_array.*)))

  KEEP (*(.init_array*))

  PROVIDE_HIDDEN (__init_array_end = .);

 } >RAM_EXEC

 .fini_array :

 {

  PROVIDE_HIDDEN (__fini_array_start = .);

  KEEP (*(SORT(.fini_array.*)))

  KEEP (*(.fini_array*))

  PROVIDE_HIDDEN (__fini_array_end = .);

 } >RAM_EXEC

 /* used by the startup to initialize data */

 _sidata = LOADADDR(.data);

 /* Initialized data sections goes into RAM, load LMA copy after code */

 .data : 

 {

  . = ALIGN(4);

  _sdata = .;    /* create a global symbol at data start */

  *(.data)      /* .data sections */

  *(.data*)     /* .data* sections */

  . = ALIGN(4);

  _edata = .;    /* define a global symbol at data end */

 } >RAM AT> RAM_EXEC

  

 /* Uninitialized data section */

 . = ALIGN(4);

 .bss :

 {

  /* This is used by the startup in order to initialize the .bss secion */

  _sbss = .;     /* define a global symbol at bss start */

  __bss_start__ = _sbss;

  *(.bss)

  *(.bss*)

  *(COMMON)

  . = ALIGN(4);

  _ebss = .;     /* define a global symbol at bss end */

  __bss_end__ = _ebss;

 } >RAM

 /* User_heap_stack section, used to check that there is enough RAM left */

 ._user_heap_stack :

 {

  . = ALIGN(8);

  PROVIDE ( end = . );

  PROVIDE ( _end = . );

  . = . + _Min_Heap_Size;

  . = . + _Min_Stack_Size;

  . = ALIGN(8);

 } >RAM

  

 /* Remove information from the standard libraries */

 /DISCARD/ :

 {

  libc.a ( * )

  libm.a ( * )

  libgcc.a ( * )

 }

 .ARM.attributes 0 : { *(.ARM.attributes) }

}

Since I am pretty new with this topic, I could not exactly understand what should I do and which part should I probably change.

I did some search and ina web-site somebody told if we define the array like this, the overflow error will be removed.

uint8_t buffer2[64000] __attribute__((section(".ccmram")));

Could you please tell me that what does it mean ? what should I do if I want to store three buffer the overall size of which are around 500KB?

what is ccram and which part of my RAM is consisted of ccram ?

thank you.