MPC5xxx中的主题 Re: MPC5606B Configure variable in RAM to run

MPC5606B Configure variable in RAM to run

明伟张 — Wed, 05 Aug 2015 05:29:46 GMT

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!

Re: MPC5606B Configure variable in RAM to run

lukaszadrapa — Thu, 06 Aug 2015 12:45:05 GMT

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

Re: MPC5606B Configure variable in RAM to run

明伟张 — Fri, 07 Aug 2015 00:57:10 GMT

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!!!!

Re: MPC5606B Configure variable in RAM to run

lukaszadrapa — Fri, 07 Aug 2015 07:23:12 GMT

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

Re: MPC5606B Configure variable in RAM to run

明伟张 — Tue, 11 Aug 2015 00:40:00 GMT

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?

Re: MPC5606B Configure variable in RAM to run

lukaszadrapa — Tue, 11 Aug 2015 12:47:40 GMT

Hi,

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

Lukas

Re: MPC5606B Configure variable in RAM to run

明伟张 — Wed, 12 Aug 2015 09:01:52 GMT

thanks! the problem is OK!