TMS470 - Digital Watchdog

Hi Allan,

This is the Forum to support TMS570 series of devices..

What do you mean by locks, does it get reset or Locked ? Configure Preload register before enabaling the DWD.
Hope the Key write sequence have been followed correctly in your software.  

Please be aware that the TMS470R1 Series (including the TMS470R1A288 device) is not recommended for new designs. However, the device, tool, or software continues to be in production to support existing customers.  Please see the full 'NRDN' notice here.

Soon TI will be launching the new TMS470M series of microcontrollers.  This series will feature greater ARM CPU performance and a similar peripheral set to the TMS470R1 Series of microcontrollers.  Please come back soon for more information about the TMS470M Series of microcontrollers.  The product preview for the first two microcontrollers in the TMS470M series is available here: TMS470MF0660x - SPNS157.

Hi Prathap,

Sorry about the mixup in forums, I thought I posted it in the 470 forum but it ended up here.

I have followed (correctly i think) the configuration in SPNU244, and when I enabled the DWD via the DWCTRL register the device locks up, it does not reset.  I am at a bit of a dead end.

Thanks for the info on the new devices.  As our product has been in production for a few years now, we are required to continue support for it for another 4-5 years. Hopefully by then I will have the DWD functioning.

Allan

Hi

Our TMS470 expert is on vacation till Jan 1st week.  Sorry I have very limoted exposure to R1X devices.

I found a simple DWD test case in our data base, hope this will give some idea.

8750.dwd21.zip

Allan,

  Here is the code I use to initialize the digital watchdog timer and my calculation for the timer value:

  /*Prescaler - OSCIN = 6 Mhz.

    texp = 2^13 * (DWPRLD + 1) / OSCIN

    Therefore range of values for texp = 1.36533 ms - 5.59104 s

    let texp = 45.056 ms  DWPRLD = texp*OSCIN/2^13 - 1

    For OSCIN = 6 Mhz       DWPRDL = 33; 0x0021

  */

  DWPRLD = 0x0021;

  //Start Watchdog

  DWCTRL = 0xACED5312; //Recommended value to start DWD.

  //TO reload the DWD:

  //DWKEY = 0xE51A;

  //DWKEY = 0xA35C;

Then all I do is in my main software loop i have the following lines of code to reset the timer before it runs out.

    //To reload the DWD write in this order:

    DWKEY = 0xE51A;

    DWKEY = 0xA35C;

When you are debugging and the DWD runs out, the system freezes and if you hit the halt button in the debugger it will show you at a memory location FFFFFF8 (or something like that).  I hope this helps.