RTOS/TMS320F28335: Unexpected program execution

Paloma de la Fuente Vega

Intellectual 650 points

Part Number: TMS320F28335

Tool/software: TI-RTOS

Hello,

I am using Flash API V2.10 to execute Flash operations on TMS320F28335.

I use Flash_CallbackPtr to feed watchdog and to send a CAN message as a keep alive.

This is my callback function:

#pragma CODE_SECTION(Flash_Callback,"ramfuncs");

void Flash_Callback(void)

{

static Uint16 j= 0;

byte _p_Data[2]= {1,0}; //Erasing

EALLOW;

SysCtrlRegs.WDKEY = 0x55; /* serve watchdog #1 */

SysCtrlRegs.WDKEY = 0xAA; /* and serve watchdog #2 */

EDIS;

j++;

if(j>13900)

{

CanSendMessage(0x19D0133A, 0, _p_Data); //in ram

j= 0;

}

When the program calls to the Flash28335_Erase function the program executes the erasing and the callback (CAN message is sent). After the erasing has finished, the program execution goes I don't know where but it is not halted. After some time, the DSP is restarted.

If I suspend the execution before the restart, I always see this:

Moreover, after some investigations, I could see that declaring p_Data[2] as static solves the problem, the program execution after the erasing is normal. It doesn’t make sense to me and I guess that the real problem if somewhere else. Could you help me?

This is the development environment:

DSP: TMS320DSP28335

Compiler: 6.2.5

XDCTools: 3.30.4.52

SYS/BIOS: 6.41.0.26

CCS: v6.1

Regards,

Paloma

over 8 years ago

0 Elizabeth Joy over 8 years ago

TI__Expert 5940 points

Hi Paloma,

We've referred this thread to the TI-RTOS team for feedback.

If you haven't already, please take a look at these resources:

Debugging Video How to debug exceptions, stack overflows and memory allocation errors.
2-day workshop

Regards,
Elizabeth

0 Sal Pezzino over 8 years ago

TI__Mastermind 32995 points

It looks like 0xC128 is in RAM memory. Can yo usee what is mapped to that RAM block which contains this memory address please and report back?

sal

0 Paloma de la Fuente Vega over 8 years ago in reply to Sal Pezzino

Intellectual 650 points

Sorry, but I made a mistake and I attached the wrong screenshot.

This is the right one.

Regards,

Paloma

0 Sal Pezzino over 8 years ago in reply to Paloma de la Fuente Vega

TI__Mastermind 32995 points

Is the device resetting?

Can you check the RAM location containing the Boot ROM status please?

sal

0 Paloma de la Fuente Vega over 8 years ago in reply to Sal Pezzino

Intellectual 650 points

Actually I can't because the device is not resetting anymore. I don’t know what has changed, sorry for the inconvenience.

Now the program raises a runtime error and the execution is aborted:

This is how I call flash API functions:

DINT;

status = EEPROM_Erase();

EINT;

The error raises after the EEPROM_ERASE has finished (same with EEPROM_Write), the program hits EINT and Flash_CallbackPtr function.

Moreover, there is something I do not understand in Flash_CallbackPtr function and maybe it gives some information.

When _p_Data is declared as dynamic (byte _p_Data[2] = {2,2};), the initialization is not working correctly, both elements are set to 0. Each element should be initialize separately to have the correct value. Anyway, the program is still not working.

When _p_Data is declared as static byte _p_Data[2] = {2,2}, the initialization is correct and the program works perfectly, no error.

Regards,

Paloma

0 Sal Pezzino over 8 years ago in reply to Paloma de la Fuente Vega

TI__Mastermind 32995 points

Where is p_Data being linked to memory? What memory section is it in? You can see this from the .map file.

sal

0 Paloma de la Fuente Vega over 8 years ago in reply to Sal Pezzino

Intellectual 650 points

Thank you for your quick response.
In both cases, static or not, _p_Data is a local variable so it is not in *.map file. This is correct, isn’t it?

0 Sal Pezzino over 8 years ago in reply to Paloma de la Fuente Vega

TI__Mastermind 32995 points

If it is local to a function, then it will not show up in the .map. That is fine.

You cannot view static variables unless you are paused in that file. Have you seen what exactly is happening during the initialization both ways. Please step through the assembly to see what the difference is.

sal

0 Paloma de la Fuente Vega over 8 years ago in reply to Sal Pezzino

Intellectual 650 points

This is what I see when halting the program.

Dynamic declaration of _p_Data:

Static declaration of _p_Data:

Paloma

0 Sal Pezzino over 8 years ago in reply to Paloma de la Fuente Vega

TI__Mastermind 32995 points

This does not necessarily mean that the variable is not getting initialized. The compiler may just be initializing it just before it is being used in the first scenario. "static" and "volatile" will likely cause the compiler to initialize them at the start of the function when they are declared.

Hope this helps.

sal

0 Paloma de la Fuente Vega over 8 years ago in reply to Sal Pezzino

Intellectual 650 points

After that, I use it as data of a CAN message.
In the other side of the CAN bus, with the static declaration I receive a ‘1’, and with the other declaration I receive a ‘0’.
Can I prove it any other way?

Thank you,

Plaoma

0 Sal Pezzino over 8 years ago in reply to Paloma de la Fuente Vega

TI__Mastermind 32995 points

I cannot explain this currently. If you think this is a compiler bug, please post to the compiler forum.

One last suggestion: Look in the memory browser to see how the array is being initialized when stepping through the assembly.

How is the assembly different for the initialization?

sal

0 Paloma de la Fuente Vega over 8 years ago in reply to Sal Pezzino

Intellectual 650 points

Hello,

I think I found what is happening.

As you suggested I have stepped through assembly code and I could see that the DSP needs a Flash address to decode an array dynamic initialization.

This code is in Flash_CallbackPtr so it can’t have access to that FLASH address.

In the other initializations, the decoding doesn’t need a FLASH address so the API works properly.

What do you think?

Could that explain also the unpredictable execution or the runtime error?

Regards,

Paloma

0 Sal Pezzino over 8 years ago in reply to Paloma de la Fuente Vega

TI__Mastermind 32995 points

This is possible. Flash API code and code which calls the Flash API needs to be loaded to flash but then copied and run from RAM.

sal

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RTOS/TMS320F28335: Unexpected program execution