TMS320F28P659DK-Q1: How to trigger a ITRAP

W Z

Expert 2120 points

Part Number: TMS320F28P659DK-Q1

Tool/software:

Hello TI expert,

I want to trigger a ITRAP, and use the below method in the main loop.

Define a pointer and point to a illegal address, then write and read the value of it.

But I did not enter into any interrupt.

Is something wrong with my method?

volatile uint32_t *TestOverRangePoint = (uint32_t *)0xFFFFFFFF;
volatile uint32_t TestData = 0;

for (;;)
{
*TestOverRangePoint = 0x01;
TestData = *TestOverRangePoint;

}

Another question is that I want to write the handler for ITRAP.

Does TI provide the example that how to record the return address value on the stack in the ITRAP handler?

7 months ago

+1 Prarthan Bhatt 7 months ago

TI__Genius 10075 points

Hi W Z,

Please refer to the C28 CPU guide- https://www.ti.com/lit/ug/spru430f/spru430f.pdf section 3.6 and 3.5.2

Easiest way would to execute TRAP #19 instruction that corresponds to ITRAP

Thanks.

0 W Z 7 months ago in reply to Prarthan Bhatt

Expert 2120 points

Thanks for your help. It is really the easiest way to execute TRAP #19

void trigger_trap19() {
asm(" TRAP #19 ");
}

Could you please help check the below question?

Is something wrong with my method?

I want to test that access to an invaild memory, then enter into the illegal interrupt.

volatile uint32_t *TestOverRangePoint = (uint32_t *)0xFFFFFFFF;
volatile uint32_t TestData = 0;

for (;;)
{
*TestOverRangePoint = 0x01;
TestData = *TestOverRangePoint;

}

0 W Z 6 months ago in reply to W Z

Expert 2120 points

Hello, Could please help reply?

0 Prarthan Bhatt 6 months ago in reply to W Z

TI__Genius 10075 points

Hi WZ,

W Z said:
I want to test that access to an invaild memory, then enter into the illegal interrupt.

Can you point to the reference document for the statement above ?

From C28x Guide I only see the below source for ITRAP:

Thanks

0 W Z 6 months ago in reply to Prarthan Bhatt

Expert 2120 points

The first one, invalid addressing mode. Is there document that clarify more inforamtion about invalid instruction, and when the opcode value is 0x0000 and 0xFFFF

0 Prarthan Bhatt 6 months ago in reply to W Z

TI__Genius 10075 points

WZ,
That's is Illegal value read from program memory during an instruction fetch.

Illegal OPCODE fetch values are 0000, FFFF, or any value that does not match a defined opcode.

Thanks.

0 W Z 6 months ago in reply to Prarthan Bhatt

Expert 2120 points

I cannot understand, what is illegal value read from program memory. Could you please show an example?

Got your OPCODE define. But When do the normal coding, how can bring in a not defined opcode?

0 Prarthan Bhatt 6 months ago in reply to W Z

TI__Genius 10075 points

WZ,

In a case where you start executing from memory which has either all 0000 or FFFF unintentionally then you may end up getting ITRAP

Here is a scenario explained in this e2e : https://e2e.ti.com/support/microcontrollers/c2000-microcontrollers-group/c2000/f/c2000-microcontrollers-forum/1313506/tms320f28335-28335-illegal-instruction-execution-problem/4992071#4992071

Thanks

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TMS320F28P659DK-Q1: How to trigger a ITRAP