Why Can’t I see Watchdog Reset in RSTC? (SAMV71)

Log in or register to post comments
Go To Last Post
3 posts / 0 new
Author
Message
CpuDude
CpuDude's picture
Level: Wannabe
Joined: Fri. Oct 13, 2017
Posts: 53 View posts
#1
Posted by CpuDude: Thu. Feb 4, 2021 - 09:14 PM
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

I have written code to determine the cause of a Reset on a SAMV71. The RSTC Status Register contains a code that can tell me if the CPU reset was caused by General Reset (powerup?). Watchdog Reset, Software Reset, Or USER RST which is NRST pin pulled low (Hardware Reset).

 

I can detect General Reset, Software Reset and Hardware Reset. However, a Watchdog Reset gives me the same code as Hardware Reset (USER_RST).

I have the following code to generate a Watchdog Reset.

 

while(1);

 

This code does reset my processor. However, the RSTC Status register still says USER_RST not WDT_RST.

Can anyone tell me why?

This topic has a solution.

Tags:

Tools, Atmel Software Framework (ASF) and Atmel Start (ASFv4) (ARM-related), solved
Last Edited: Fri. Feb 11, 2022 - 02:24 PM
Top
chueg
chueg's picture
Level: New Member
Joined: Fri. Oct 22, 2021
Posts: 2 View posts
Posted by chueg: Wed. Oct 27, 2021 - 02:10 PM
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Hey CpuDude,

 

the same Problem occured to me, could you solve the problem?

It seems, that the voltage level of the NRST pin doesn't rise fast enough. So we soldered out the Capacitance C104 and reduced the resistor R106 to 10kOhm (so we match the NRST slope requirement of 1/f_slck) on the Xplained ultra board.

 

Cheers,

Christoph

Last Edited: Wed. Oct 27, 2021 - 03:49 PM
Top
CpuDude
CpuDude's picture
Level: Wannabe
Joined: Fri. Oct 13, 2017
Posts: 53 View posts
This reply has been marked as the solution. 
Posted by CpuDude: Fri. Feb 11, 2022 - 02:23 PM (Reply to #2)
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Christoph,

 

Thanks for your reply. I think you are correct.  I eventually found the following in the datasheet":

"After a watchdog overflow occurs, the report on the RSTC_SR.RSTTYP may differ (either WDT_RST or USER_RST) depending on the external components driving the NRST pin. For example, if the NRST line is driven through a resistor and a capacitor (NRST pin debouncer), the reported value is USER_RST if the low to high transition is greater than one SLCK cycle."
 

Top