Reconfiguring Watchdog Timeout Multiple Times in Same Power Cycle — FS6500 / FS4500 SBC

[yogesh95]

Hello,

I am working with the FS6500 / FS4500 Safety Power System Basis Chips and I have a question regarding watchdog reconfiguration within the same power cycle.

In my use case, the bootloader configures the watchdog with a timeout of 1 second. After the software jumps to the application, I would like to reconfigure the watchdog timeout to 256 ms.

My question is:
Is it allowed and technically supported to reconfigure the watchdog timeout multiple times within the same power cycle on FS6500 or FS4500 devices?
If yes, are there any restrictions, specific sequences, or register access limitations that should be considered when changing the watchdog timeout after initial configuration?

Thank you in advance for your support.

[JozefKozon · Accepted solution]

Hello Yogesh,

My question is:
Is it allowed and technically supported to reconfigure the watchdog timeout multiple times within the same power cycle on FS6500 or FS4500 devices?
If yes, are there any restrictions, specific sequences, or register access limitations that should be considered when changing the watchdog timeout after initial configuration?

[A] Yes, it is allowed to reconfigure the watchdog timeout within the same power cycle. It is also possible to se the Watchdog Window to infinitely open (allowed only in INIT_FS phase), meaning that if no watchdog refresh is sent, no error is generated.

You can reconfigure the watchdog timeout in the INIT_FS phase or in Normal mode. 

With Best Regards,

Jozef