topic Re: How to moved variable to certain section of RAM memory in MPC5xxx

How to moved variable to certain section of RAM memory

vikasb — Mon, 12 Dec 2016 06:40:30 GMT

I want to know is there in method to align the indivialial variable declared is such way that blow variable can be moved

to some section of RAM memory,

I want align below variable to RAM memory section to 0x40005000

volatile real32_T Main_KD = 6.0F; RAM address = 0x40005000
volatile real32_T Main_KD_limit = 1.0F; RAM address = 0x40005004
volatile real32_T Main_KP1 = 4.0F; RAM address = 0x40005008
volatile real32_T Main_KP2 = 2.0F; RAM address = 0x4000500C
volatile real32_T Main_KP_conv1 = 0.15F; so on
volatile real32_T Main_KP_conv2 = 1.0F;
volatile real32_T Main_Threshold_off = 1.0F;
volatile real32_T Main_Threshold_on = 2.0F;
volatile real32_T Main_deadbandA = 0.0F;
volatile real32_T Main_deadbandB = 0.0F;

Re: How to moved variable to certain section of RAM memory

lukaszadrapa — Tue, 13 Dec 2016 13:38:08 GMT

Hi,

which device and which IDE do you use?

Regards,

Lukas

Re: How to moved variable to certain section of RAM memory

vikasb — Tue, 13 Dec 2016 13:41:11 GMT

Hello Luncas,

I’m using the MPC5553 controller with codewarrior IDE v2.8 for developing the software.

-Vikas

Re: How to moved variable to certain section of RAM memory

lukaszadrapa — Tue, 13 Dec 2016 13:57:32 GMT

Here is simple example which I copied from some old test project.

In linker file:

MEMORY

{

...

my_ram: org = 0x40030000, len = 0x0000C000 //just example, use addresses you need

...

}

SECTIONS

{

...

.__my_ram: {} > my_ram

...

}

In *.c file:

#pragma push
#pragma section all_types ".__my_ram" ".__my_ram" data_mode=far_abs
volatile unsigned int data1;

volatile unsigned int data2;

volatile unsigned int data3;
#pragma pop

The order of data1, data2, data3 in RAM will be the same as order in this section. You can check it in the map file.

Regards,

Lukas

Re: How to moved variable to certain section of RAM memory

vikasb — Wed, 14 Dec 2016 13:25:10 GMT

Thanks for help, now I could manage the RAM memory addressing as per my need.