using external memory as RAM

Subash,

I suspect the code is failing because you have initialized global variables or local static variables in the .ebss section.  The initial values of these vars will be initialized by the _c_int00 function (from the RTS library), which runs prior to main().  Your XINTF is not configured at that time, so the intialization fails.

You either need to put all your initialized globals (and statics) in a seperate named section that you link to internal RAM, or you need to intialize the XINTF prior to main().  The later can be done.  You could use assembly code to setup the XINTF before calling _c_int00 (if you are using the code examples in ControlSuite as your model, the call to _c_int00 is made in the CodeStartBranch.asm file).  Alternately, you can probably get away with using C-code to init the XINTF prior to _c_int00 as long as you don't use any initialized global variables or static locals in the function.  At the end of the XINTF init function, you call _c_int00 (which in turn calls main).

Regards,

David

1856.f28335_xbee_ticcs.zip

Hi David,
I tried putting the *.ebss section into the Flash memory and then loading from FLASH, running in external memory, that too dint work out.
I don't know how to initialize the XINTF section before main, i have attached the code, kindly let me know how to do it.

Subash,

Subash Chandar Athikessavan said:

I tried putting the *.ebss section into the Flash memory and then loading from FLASH, running in external memory, that too dint work out.

The .ebss is an uninitialized section.  It must be linked to RAM.  You cannot link it to read-only memory such as flash.

To initialize the XINTF prior to main(), you should modify the function 'code_start' in the file DSP2833x_CodeStartBranch.asm to branch to your XINTF init function rather than _c_int00.  You can write the XINTF init function in C as long as you don't use any global variables or initialized static variables (and why would you.  The init function is nothing but assignment statements linke *MyRegister = 0x12345678;).  At the end of the init function, you should branch to _c_int00.

- David

Hi David,
 I tried intializing the Xintf before _c_int00 in codestartbranch.asm(), Have a look at the code, but still the same issue

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

WD_DISABLE    .set    1        ;set to 1 to disable WD, else set to 0

;    .ref _start_ebss
;    .ref _end_ebss
    .ref _c_int00
    .global code_start

***********************************************************************
* Function: codestart section
*
* Description: Branch to code starting point
***********************************************************************

    .sect "codestart"

code_start:
    .if WD_DISABLE == 1
        LB wd_disable       ;Branch to watchdog disable code
    .else
;    movl XAR0,#_start_ebss
;     mov AL,#0
;     mov AH,#(_end_ebss - _start_ebss - 1)
;     rpt AH || mov *XAR0++,AL
   PCLKCR3= 0x3700;                          
   GPBMUX1= 0xFFFFFFC0;   /* GPBMUX1 */
   GPAMUX2 = 0xFF000000;   /* GPAMUX2 */  
   GPCMUX2 = 0x0000AAAA;   /* GPCMUX2 */  
   GPCMUX1 = 0xAAAAAAAA;   /* GPCMUX1 */
   XTIMING0= 0x0043FFFF;    /* Zone0 */
   XTIMING6= 0x0043FFFF;    /* Zone6 */
   XTIMING7= 0x0043FFFF;    /* Zone7 */
        LB _c_int00         ;Branch to start of boot.asm in RTS library
    .endif

;end codestart section


***********************************************************************
* Function: wd_disable
*
* Description: Disables the watchdog timer
***********************************************************************
    .if WD_DISABLE == 1

    .text
wd_disable:
    SETC OBJMODE        ;Set OBJMODE for 28x object code
    EALLOW              ;Enable EALLOW protected register access
    MOVZ DP, #7029h>>6  ;Set data page for WDCR register
    MOV @7029h, #0068h  ;Set WDDIS bit in WDCR to disable WD
    EDIS                ;Disable EALLOW protected register access
;    PCLKCR3= 0x3700;                          
;   GPBMUX1= 0xFFFFFFC0;   /* GPBMUX1 */
;   GPAMUX2 = 0xFF000000;   /* GPAMUX2 */  
;   GPCMUX2 = 0x0000AAAA;   /* GPCMUX2 */  
;   GPCMUX1 = 0xAAAAAAAA;   /* GPCMUX1 */
;   XTIMING0= 0x0043FFFF;    /* Zone0 */
;   XTIMING6= 0x0043FFFF;    /* Zone6 */
;   XTIMING7= 0x0043FFFF;    /* Zone7 */
    LB _c_int00         ;Branch to start of boot.asm in RTS library

    .endif

;end wd_disable



    .end
    
;//===========================================================================
;// End of file.
;//===========================================================================

My linker file is

MEMORY
{
PAGE 0:
    BEGINRAM:     origin=0x0, length=0x2
    RAMM0:     origin=0x2, length=0x3fe
    OTP:     origin=0x380400, length=0x400
    FLASH:     origin=0x300000, length=0x3fff6
    BEGINFLASH:     origin=0x33fff6, length=0x2
    CSM_PWL:     origin=0x3f7ff8, length=0x8
    IQTABLES:     origin=0x3fe000, length=0xb50
    IQTABLES2:     origin=0x3feb50, length=0x8c
    FPUTABLES:     origin=0x3febdc, length=0x6a0
    ROM:     origin=0x3ff27c, length=0xd44
    RESET:     origin=0x3fffc0, length=0x2
    VECTORS:     origin=0x3fffc2, length=0x3e
   // RAML4L7:     origin=0xc000, length=0x4000
    RAML0L3:     origin=0x8000, length=0x8000
    ADC_CAL:     origin=0x380080, length=0x9
    ZONE7P:     origin=0x200000, length=0x10000
PAGE 1:
   // RAML0L3:     origin=0x8000, length=0x4000
    RAMM1:     origin=0x400, length=0x400
   // PROG_RAM:     origin=0x3F8000, length=0x1000
    ZONE7D:     origin=0x210000, length=0x10000

}
SECTIONS
{
    .vectors:     load = 0x000000000
    .text:     > FLASH, PAGE = 0
    .switch:     > FLASH, PAGE = 0
    .bss:     > RAML0L3, PAGE = 0
    .ebss:     > ZONE7D, PAGE = 1
    //.ebss:    > ZONE7D,       PAGE = 1, LOAD_START(_start_ebss),LOAD_END(_end_ebss)
    .far:     > RAML0L3, PAGE = 0
    .cinit:     > FLASH, PAGE = 0
    .pinit:     > FLASH, PAGE = 0
    .const:     > FLASH, PAGE = 0
    .econst:     > FLASH, PAGE = 0
    .reset:     > RESET, PAGE = 0, TYPE = DSECT
    .data:     > RAML0L3, PAGE = 0
    .cio:     > RAML0L3, PAGE = 0
    .sysmem:     > RAML0L3, PAGE = 0
    .esysmem:     > RAML0L3, PAGE = 0
    .stack:     > RAMM1, PAGE = 1
    .rtdx_text:     > FLASH, PAGE = 0
    .rtdx_data:     > RAML0L3, PAGE = 0
    IQmath:     > FLASH, PAGE = 0
    codestart:     > BEGINFLASH, PAGE = 0
    csmpasswds:     > CSM_PWL, PAGE = 0
    csm_rsvd:     > RAMM0, PAGE = 0
    ramfuncs:     LOAD = FLASH,
        RUN = RAMM0,
        LOAD_START(_RamfuncsLoadStart),
        LOAD_END(_RamfuncsLoadEnd),
        RUN_START(_RamfuncsRunStart),
        PAGE = 0
    .adc_cal:     > ADC_CAL, PAGE = 0 , TYPE = NOLOAD
    IQmathTables:     > IQTABLES, PAGE = 0 , TYPE = NOLOAD
    IQmathTables2:     > IQTABLES2, PAGE = 0 , TYPE = NOLOAD
    FPUmathTables:     > FPUTABLES, PAGE = 0 , TYPE = NOLOAD
}
-l "C:\Program Files\MATLAB\R2011b\toolbox\idelink\extensions\ticcs\c2000\c2833xPeripherals.cmd"

The intialization part, i got it from gel file in "xintf_Enable()" function, Kindly let me know if i am wrong

Hi,

 I have been stuck in external memory initialization, I have put by codestartbranch.asm() code in my previous post.
Can anybody tell me what is the issue with the code ?

Hi David,

 Thank you very much for helping me to resolve the issue, it is working fine now, I usually use Matlab to program F28335, hence i never got exposed to programming using CCS, thats why i would have made silly mistakes. Thanks a lot