PIC16877 gets stuck in the main

[curious]

Hiiii everybody.

I have a circuit with 16F877.

I use 20 Mhz cyristal frequency.

But, sometimes, before going to any interrupt
routine, in the main, watch dog is timing out and reseting the PIC for 1 or 2 or 3 times. (ramdomly differs) Then working fine.

But, for push button resets or power-on resets, rarely it is the same as above. it is working properly.

For sometimes, there is no WDT reseting and everything is going on perfectly.

Changing WDT time out peryot (18, 36 ... ms etc) is not making any difference.

I definetely know that it is sticking in the main. there is no any infinite loop in the main.

If it jumped from the main to the first ISR or any other ISR, some LEDs and LCD display would show any characters that are normally seen on it.

If I remove WDT in the code, it is coming to the ISRs, but it gets stuck for some times.


What should I do?

HELPs complitely appreciated.


curious

[Mark]

You should post a small sample program that demonstrates the problem as well as the compiler version. Make sure to use the code button when posting code.

[curious]

hiii Mark....


I use PCM ver 3.155.


problem solved.



I just put the line enable_interrupts(global); in do/while loop (in the main)

it was like this :


....... // some lines

ext_int_edge(L_TO_H);
enable_interrupts(INT_EXT);

..... // some lines


enable_interrupts(global);

do{

;

} while (1)


and made them like this....


....... // same as above

ext_int_edge(L_TO_H);
enable_interrupts(INT_EXT);

..... // same as above


do{

enable_interrupts(global);


} while (1)



Startup problem is vanished completely !

Is there any body who can explain this ?



curious

[Guest]

[curious]

thanks guest...