MPC5606B Configure variable in RAM to run

[明伟张]

firstly,the global variable are configured to flash address which i defined; i hope the variable copy to RAM address which i defined when workspace start running;

can offer me sample code?

thanks!

[lukaszadrapa]

Hi,

here is the example:

In linker file I added myROM and myRAM segment:

MEMORY

{

    resetvector:           org = 0x00000000,   len = 0x00000008

    init:                   org = 0x00000020,   len = 0x00000FE0   

    exception_handlers:    org = 0x00001000,   len = 0x00001000

    internal_flash:        org = 0x00002000,   len = 0x000FD000

    myROM:                     org = 0x000FF000,   len = 0x00001000

    internal_ram:          org = 0x40000000,   len = 0x00011000

    myRAM:                       org = 0x40011000,   len = 0x00001000

    heap  :                org = 0x40012000,   len = 0x00001000

    stack :                org = 0x40013000,   len = 0x00001000

}

Then use this syntax in SECTION:

SECTIONS

{

...

.myRAM BIND(ADDR(myRAM)) LOAD (ADDR(myROM)): {} > myRAM

...

}

And then in *.c file:

#pragma push

#pragma section sdata_type ".myRAM" ".myRAM"

unsigned int my_var1 = 0x11223344;

unsigned int my_var2 = 0xAABBCCDD;

unsigned int my_var3 = 0x55556666;

#pragma pop

The initial values will be copied during startup from myROM to variables in myRAM.

Regards,

Lukas

[明伟张]

the two question is not  same! In fact,for exampel:

i define a variable in flash as follow:

MEMORY

{

...

my_flash:

org = 0x003FF000,   len = 0x00001000

...

}

SECTIONS

{

...

.__my_flash LOAD (0x003FF000): {} > my_flash

...

}

In *.c file:

#pragma push

#pragma section all_types ".__my_flash" ".__my_flash "

uint32_t test = 0x1234;

#pragma pop

if it is OK,i want the variable "test" initial values can be copied during startup from my_flash to variables in myRAM.

so how to configure the myRAM in  *.c file:?? thanks! can offer me a sample code?

thanks verry verry much!!!!

[lukaszadrapa]

Hi,

you have to do it exactly in the same way as I showed in my previous post if you want to have variable in RAM that is initialized during startup.

The above can be used only for constant in flash.

Regards,

Lukas

[明伟张]

Hi,

I know,thanks.

but i also have a question,the variable is configured in Flash,i want the variable copy to ram address which i defined before MCU run?

[lukaszadrapa]

Hi,

that's what it does. In the example above, the startup files will copy the initial values stored in myROM to myRAM.

Lukas

[明伟张]

thanks! the problem is OK!