TMS320F28386D: illegalOperation

W Z

When the program enter into the static void Interrupt_illegalOperationHandler(void).

Is there method to check the cause source?

static void Interrupt_illegalOperationHandler(void)
{
//
// Something has gone wrong. The CPU has tried to execute an illegal
// instruction, generating an illegal instruction trap (ITRAP).
//
ESTOP0;
for(;;)
{
;
}
}

over 3 years ago

0 Aswin P over 3 years ago

TI__Genius 10461 points

Hi,

Please look at the following document section 3.6 "Illegal Instruction Trap" section. This has information on how to get the offending address by looking at the contents pushed on the stack.

https://www.ti.com/lit/ug/spru430f/spru430f.pdf

The illegal-instruction trap saves the return address on the stack. Thus, you can detect the offending address by examining this saved value.

The following post would help you to understand the details.

(+) TMS320F28379D: Debugging ITRAP Interrupt_illegalOperatorHandler() - C2000 microcontrollers forum - C2000︎ microcontrollers - TI E2E support forums

Thanks

Aswin

0 W Z over 3 years ago in reply to Aswin P

Expert 2480 points

Could you please help use the example erad_ex3_stack_overflow_detect

(Comment the line like this //ERAD_enableInterruptOnAddressHit(addr_params, ERAD_HWBP1_BASE);)

It will enter into the ITRAP (static void Interrupt_illegalOperationHandler(void))

As above said " The illegal-instruction trap saves the return address on the stack. Thus, you can detect the offending address by examining this saved value."

Coud you let me know where I can check the retrun address on the stack? (Maybe CCS debug snapshot is good way to show)

How to detect the offending address by examining this saved value?

0 Aswin P over 3 years ago in reply to W Z

TI__Genius 10461 points

Hi,

In the erad_ex3_stack_overflow_detect example, it has a recursive function to fill the stack, causing the stack overflow. This is causing the ITRAP.

Thanks

Aswin

0 W Z over 3 years ago in reply to Aswin P

Expert 2480 points

Yes. We know the cause is recursive function which resulted stack overflow.

My question is below: (Assumption is we didnot know the cause, we need the below method to find the root cause)

Coud you let me know where I can check the retrun address on the stack? (Maybe CCS debug snapshot is good way to show)

How to detect the offending address by examining this saved value?

0 Vince over 3 years ago in reply to W Z

TI__Mastermind 19795 points

Hi W Z,

Thanks for your follow up question.

This thread is where most of the information for what you're asking would be. https://e2e.ti.com/support/microcontrollers/c2000-microcontrollers-group/c2000/f/c2000-microcontrollers-forum/979782/tms320f280049c-illegal-instruction-behavior---how-to-retrieve-the-offending-address/3620048#3620048

For determining the saved value, the following image is from the link: https://software-dl.ti.com/C2000/docs/c28x_interrupt_faq/html/index.html

Specifically for you: here's a link on how to read the RPC (basically return address): https://e2e.ti.com/support/microcontrollers/c2000/f/171/t/693819

So you'll have to write a short assembly stub and then can pop the RPC value to a variable in your viewer.

Regards,

Vince

C2000™︎ microcontrollers

C2000 microcontrollers forum

TMS320F28386D: illegalOperation