Watchdog was enable but sometime the MCU can stop working

[ezra]

Dear All,
Please help me for 2 problem as following:
When the LPC922 MCU running, sometime this MCU can stop working.
I have enable internal watchdog timer. Brownout is disable. Reset Pin is disable.
I think when the watchdog is enable, it's impossible the MCU can stop working.
Watchdog timer with separate on-chip oscillator.
I have checked my program is fine.

When the I/O pin has no connect, which one is better for port output mode as following:
1. Bidirectional
2. Push-Pull
3. Input Only (High Impedance)
4. Open Drain

Thanks & regards.

 

[bobcat1]

Re: Watchdog was enable but sometime the MCU can stop workin

Hi

Why did you disable BOR & POR - if you have power supply problem they can help you

also check your oscillator also source for problem


All the best

Bobi

 

[ezra]

Re: Watchdog was enable but sometime the MCU can stop workin

Thanks Bobi,
I have enable BOR and POR.
How's to check the oscillator also source?

Thanks & regards.

 

[bobcat1]

Re: Watchdog was enable but sometime the MCU can stop workin

Hi

You can check oscillator by scop viewing the signal - or using a simple VOM and mesuring 1/2 vcc on the oscillator pin (not recomended test - this will only tell you whether the oscillator is working)


BR

Bobi

 

[slhugo]

Re: Watchdog was enable but sometime the MCU can stop workin

what is watchdog time out period ?

is source code exceeding time out periods between watchdog timer resets ?

my experience says only reset watchdog timer at beginning of housekeeping
subroutines.

are any interupt routines occurring during watchdog timer reset subroutine ?

my experience says watchdog timer reset routine should have mutiple resets
that equal or exceed the number of enabled interupts.

good luck

hugo

 

[mg_designs]

check your oscillator also source for problem