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Help: Placing data at an absolute memory location in RAM

Mrt_Nsk
Intellectual 270 points

Hello everyone,

I wanted to place some data (variables) at an absolute memory location in the RAM. For example i want to define an array of 100 integers and place it at a specific location in the RAM. How do i achieve this and where can i find the related documentation and examples?

Thanks!

  • 0
    TI__Genius 16195 points

    Hi there,

     

    It all depends on which compiler you are using too. Here is a documentation that can get you started.

    http://www-s.ti.com/sc/techlit/slau157

    goto Appendix C.3.

     

  • 0
    Genius 3330 points

    You can try the following:

    // locations in information memory segments
    #define DATA1            (*(unsigned int*)0x1040)
    #define DATA1            (*(unsigned int*)0x1042)
    #define DATA3            (*(unsigned int*)0x1044)
    etc.

    Use the RAM addresses for your chip 

    Or use the linker:

    //  Code

    -Z(CODE)CSTART=8080-FFDF                   //code starts after data

    -Z(CODE)CODE=8080-FFDF


    // Constant data
    -Z(CONST)GAGE_DATA=8000-807F                                     //where my data is going. See code snip below
    -Z(CONST)DATA16_C,DATA16_ID,DIFUNCT,CHECKSUM=8000-FFDF

     

    #pragma location="GAGE_DATA"                // 8000-8079
    const struct gage_data Gage_Data =
    {
      "1.00",                                   // Firmware version
      __DATE__,                                 // Day & Time of compile
      __TIME__,
      "M241",                                   // Model no.
      "OU812",                                  // Serial no.
      "calibrator"                                  // who calibrated
    };

    Again, use the RAM addresses for your chip.

    I've only done it with flash but the linker tells you where RAM is.

  • 0 in reply to William Goh
    Intellectual 270 points

    Hi William,

    Thanks for the reply!

    I am using CCE v3. I have read the documentation already and i tried accordingly. Actually i wanted to place an array at an absolute memory location in RAM. I was able to place the array at the required memory location but i cannot see the array in the watch window while debug?

    I also didnt understand where exactly does the memory allocation takes place, because in the linker cmd file i just defined the name of the array, the actual size of the array is defined in the source file where the array is declared as an extern variable? I have shown below what i have done in the code:

    /* Linker cmd file entry */

    array_int = 0x01C00;

    /* end */

    /*Source C file Entry  */

    extern unsigned int array_int[10];

    /* end */

    why I am not able to see array_int in the watch window?

    Thanks!

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