Does the watchdog timer reset the RTC time?

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cross mob
Anonymous
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I would like to know if the current time needs to be saved somewhere like in flash to be preserved during a watchdog reset or will the watchdog reset not affect the RTC?

Thank you.

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MeenakshiR_71
Employee
Employee
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No, Watchdog reset should not reset the RTC. RTC is in backup domain and its reset is linked to backup domain reset. Backup domain can be reset during the following cases -

  1. When you have externally shorted VDDD and VBACKUP in your design (and selected vBackupSource as "VDDD" in cydwr System settings), PSoC Creator generated start-up code will reset backup domain for any POR/XRES event. For all other cases like SW reset, WDT reset etc., backup domain (RTC) is not reset.
  2. When VBACKUP falls below the min voltage (1.4 V, irrespective of VDD supply). This is sort of Power-On-Reset for the backup domain.
  3. When you call Cy_SysLib_ResetBackupDomain() in the code, this again is irrespective of what your VDD is (however VBACKUP needs to be above 1.4 V for this call to work - for obvious reason ).

Let me know if you need any further clarification.

The above info should be present in Chapter 18 "Backup System" of the PSoC 6 Architecture TRM.

Regards,

Meenakshi Sundaram R

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MeenakshiR_71
Employee
Employee
100 likes received 50 likes received 25 likes received

No, Watchdog reset should not reset the RTC. RTC is in backup domain and its reset is linked to backup domain reset. Backup domain can be reset during the following cases -

  1. When you have externally shorted VDDD and VBACKUP in your design (and selected vBackupSource as "VDDD" in cydwr System settings), PSoC Creator generated start-up code will reset backup domain for any POR/XRES event. For all other cases like SW reset, WDT reset etc., backup domain (RTC) is not reset.
  2. When VBACKUP falls below the min voltage (1.4 V, irrespective of VDD supply). This is sort of Power-On-Reset for the backup domain.
  3. When you call Cy_SysLib_ResetBackupDomain() in the code, this again is irrespective of what your VDD is (however VBACKUP needs to be above 1.4 V for this call to work - for obvious reason ).

Let me know if you need any further clarification.

The above info should be present in Chapter 18 "Backup System" of the PSoC 6 Architecture TRM.

Regards,

Meenakshi Sundaram R