Watchdog priority

Masky

Other Parts Discussed in Thread: TMS320F28016

Hello everyone,

I'm working with the TMS320F28016 DSP and CCS3.3V. I've implemented a wathdog function in my code, and right now I'm trying to test this function.

In order to do that, I execute a while(1) in differents places, and I wait until the wathdog interrupt is triggered . In the main loop I haven't any problem, but in some interrupts the watchdog is never triggered , for example if I execute a while (1) into the CPU-timer TINT0.

Reading the "TMS320x280x, 2801x, 2804x DSP System Control and Interrupts Reference Guide", the watchdog interrupt and TINT0 have the same priority, so if there is a infinite loop in the second one, the watchdog interrupt never happen.

Can I get a higher priority in the watchdog? Or there is other solution?

Thanks.

over 10 years ago

0 Igor Gorbachev over 10 years ago

Guru 20525 points

Hello!

Perhaps you apply Watchdog Interrupt Mode instead Watchdog Reset Mode (refer please to chapter 3.4.2 of your RG). The mode select is set through SysCtrlRegs.SCSR..bit.WDEINT bit. You can refer to this link also http://e2e.ti.com/support/microcontrollers/c2000/f/171/t/297596.aspx

Regards,

Igor

0 Masky over 10 years ago in reply to Igor Gorbachev

Intellectual 900 points

Hello Igor!!! Thank you for your answer.

I have set up the WD as a Watchdog Reset Mode , so if there is an infinite loop into the TIMER 0, there is a reset. But, in other parts, I need to write in an external EEPROM, so there is a reset too. Summarize:

1.- WD as a Watchdog Interrupt Mode.

The WD doesn't work when an infinite loop is placed into a interrupt with the same priority.

2.-WD as a Watchdog Reset Mode.

The WD works fine when there is an infinite loop, but not when there is a writting in an external EEPROM.

A possible solution? Maybe to disable the WD before the writing and enable after, but I'm not very agree.

Any idea?

0 Igor Gorbachev over 10 years ago in reply to Masky

Guru 20525 points

Hi Masky!

Masky said:

I have set up the WD as a Watchdog Reset Mode , so if there is an infinite loop into the TIMER 0, there is a reset. But, in other parts, I need to write in an external EEPROM, so there is a reset too.

The WD works fine when there is an infinite loop, but not when there is a writting in an external EEPROM.

Maybe to disable the WD before the writing and enable after

Clarify please some thing. You want to say that you do not have enough time to finish the writing procedure before reset from the watchdog. Do I understand? Does the writing procedure take a lot of time (more (1/(OSCCLK/512))*256) ?

Regards,

Igor

0 Masky over 10 years ago in reply to Igor Gorbachev

Intellectual 900 points

Hello Igor!

Exactly, the writing time is bigger than the WD reset time.

0 Igor Gorbachev over 10 years ago in reply to Masky

Guru 20525 points

Hi Masky!

For more clearly understanding. Your writing procedure is the atomic operation or one can be divided on several elementary operations?

Regards,

Igor

0 Masky over 10 years ago in reply to Igor Gorbachev

Intellectual 900 points

Hi Igor,

Yes, my operation can't be divided. Why WD interrupt priority cannot incresed? This is very usual operation in microcontrollers, no?

0 Igor Gorbachev over 10 years ago in reply to Masky

Guru 20525 points

Masky,

you can look at this link http://processors.wiki.ti.com/index.php/Interrupt_Nesting_on_C28x just in case but it seems the best way if you just will increase watchdog interval up to value needed for writing operation could be finished before WD reset:

Twd = (1/(OSCCLK/512/x))*256

where x = 1,2,4,8,16,32,64

Regards,

Igor

0 Masky over 10 years ago in reply to Igor Gorbachev

Intellectual 900 points

Thanks Igor.

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Watchdog priority