RAM contents getting disturbed after external watchdog reset

PARSARAM SRINIVAS

Other Parts Discussed in Thread: TMS320F28075

I am using TMX320F28377D for my application, where i have to know a reset due to external watchdog(this is required to evaluate the external watchdog timer itself). We use a loop counter (global variable) till the watchdog resets. After reset we read the content f the variable to determine its validity. But the content is not available after reset. We tried to bypass _c_int00 routine so that, up on reset variables are not cleared. Please let me know the complete and clear procedure to retain RAM variables upon soft resets.

We are running code from flash.

Thanks in advance...

Regards,

Srinivas Parasaram

over 11 years ago

0 Vivek Singh over 11 years ago

TI__Guru** 116601 points

Hi Srinivas,

This device has RAM INIT feature which clears all the RAMs. BOOT-ROM code uses this feature to clear all the RAMs on any RESET which toggles XRSn pin. Since WD reset toggles XRSn pins, all the RAM content get clear. Plesae refer "3.12 CPU1 Boot ROM Flow Chart" in TRM for complete BOOT flow.

Is it possible to save this variable in some location which doesn't get CLEAR on WD reset?

Regards,

Vivek Singh

0 PARSARAM SRINIVAS over 11 years ago in reply to Vivek Singh

Prodigy 60 points

Hi Vivek,

Thanks for the reply.

Do you mean , any external memory or some memory with in the controller (CPU2 memory)? Is there any such RAM within CPU1 or CPU2 (Shared RAM). If yes, we can store the variable in that place. Is it Ok?

Regards,

Srinivas P

0 Vivek Singh over 11 years ago in reply to Vivek Singh

TI__Guru** 116601 points

For example following are two registers which are used for HIBERNATE mode and get reset by power on reset only (not by XRSn).

HIBBOOTMODE

ORESTOREADDR

If your application is not using the HIBERNATE mode then you can use these register location (refer TRM for detail) to store the variable.

Regards,

Vivek Singh

0 PARSARAM SRINIVAS over 11 years ago in reply to Vivek Singh

Prodigy 60 points

Thank you Mr.Vivek,

HIBBOOTMODE worked out

0 toby lou over 8 years ago in reply to Vivek Singh

Prodigy 210 points

Hi Vivek,

I have the similar application requirements to the OP. I am using a TMS320F28075 device, and using the HIBBOOTMODE also worked for me. I may want to store more information to diagnose the WDT cause. Are there any other registers (other than HIBBOOTMODE and IORESTOREADDR), or RAM locations, that do not get reset on XRSn?

Thanks!

0 Vivek Singh over 8 years ago in reply to toby lou

TI__Guru** 116601 points

Toby, All the RAMs get initialized on XRSn. If you have lot's of data to store then Flash would be better option.

0 toby lou over 8 years ago in reply to Vivek Singh

Prodigy 210 points

Thanks for the clarification!

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RAM contents getting disturbed after external watchdog reset