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

[Ioannis]

What is the duration of this reset, if it is reset?

You may add a PAUSE 1000 at the beggining of the program and see if this duration is increased. This will confirm that PIC is indeed reseting.

Ioannis

[richard]

It is definitely a reset, a look at the lst file shows that the looped code segment has no pbp statements in it that generate a clwdt instruction

that loop does the the same thing for every pic chip i tried. its not really a practical loop more a curiosity

[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)