Watchdog timer don't work on PIC18f67J94

[brankobr]

I configured PIC18F67J94-I/PT as in pictures in attachment, nowhere in code didn't put CLRWDT instruction, and I expect that PIC reset after some time, but reset never happens. Can someone help me, please?

[darko.ilijevski]

Hello,

Have you checked the config/status registers, making sure the related bits are not set property? Meanwhile, I will go through the datasheet and check if I can find a solution since we do not currently have that MCU at hand, so I can't test myself. I had doubts previously if the clock source has to be manually enabled, but the selected LPRC clock should be always ON if WDT is enabled.

EDIT: I did compare the registers with the datasheet (page 554) and think I found the problem: the parameter is named a bit counterintuitive. 'Enabled' setting actually enables software-controlled WDT by using the SWDTEN bit:

WDT.jpg (24.11 KiB) Viewed 1423 times

The highlighted parameter is called "Watch Dog Timer Enable > Enabled" in mikroC PRO. This will set the WDT bits of the CONFIG6H register to 10. You can see in the screenshot above what it actually means.
I don't know if this was the intended use, but if you want WDT to operate autonomously of the software, you should set the configuration parameter as on the image below:

WDT_cfg.jpg (7.9 KiB) Viewed 1429 times

Please, let me know if you managed to solve your issue.

Best regards,
Darko

[brankobr]

I tried to do this, and now all works as expected. I supposed that there is a bug in compiler because it's very unlikely that the watchdog system in a PIC does not work.

[darko.ilijevski]

Great, I am happy it works.
My originally wrong assumption about the internal clock led me to check the config registers, just in case.

In either case, I wish you success with your project.

Happy holidays and best regards,
Darko