SOLVED - PIC seems to RESET unless I add a PAUSE in Mainloop

[Demon]

I was testing a new breadboard layout and PIC config; to make sure I had a heartbeat before piling more code.

[Ioannis]

Since on power up the SEN bit of the WDTCON0 register is at 0 (Watchdog disabled), why does that chip resets itself?

Ioannis

[HenrikOlsson]

Because if the WDTE bits in CONFIG3 is anything but 0b01 the SEN bit is ignored and the CONFIG block of the code contains _WDT_ON which, according to the .INFO file for the device means

 _WDTE_ON	    ;WDT enabled regardless of sleep; SWDTEN ignored

If you want software control of the WDT you could choose

_WDTE_SWDTEN	    ;WDT enabled/disabled by SWDTEN bit in WDTCON0

/Henrik.

[Ioannis]

But then I see no way that PBP is aware of that or can reset the WDT.

Ioannis

[Demon]

But then I see no way that PBP is aware of that or can reset the WDT.

Ioannis

I would guess by this bit?

When the WDTE bits of Configuration Words are set to ‘01’, the WDT is controlled by the SEN bit of the WDTCON0 register.

(p. 163 of datasheet)

[HenrikOlsson]

Basically the CONFIG settings allows you to force the WDT either on/off OR allow the program to turn it on/off at runtime.

As for resetting/clearing it, as long as you don't DEFINE NO_CLRWDT 1 PBP will clear/reset the WDT by inserting CLRWDT instructions into the code - it doesn't matter if the WDT is actually enabled, disabled, running or not. The instructions will be embedded in the assembly listing of the program. Unless, apparently, you do this kind of super tight loop.

[Ioannis]

Does it matter if it is a tight loop in PBP? If it was in assembly I could understand, but in Basic? Seems like a bug.

Ioannis