problem with megaAVR

[samad]

sometimes avr can't continue its correct working , but
reading it's code from itself & reprograming can solve this problem
i can't understand that how the reprograming can solve it,please help me..

[leptro]

I THINK YOU ARE IN THE WRONG FORUM!

But, it's look like a bug in your program your may do something that corrupt your flash program area or goes in a unknow state.

[kolin]

Is avr close to some high current switching device like power mosfet or so?
Have you tried different chip?

[microkid]

I do have avr's placed close to high current, But i dont see any prob (if you had a good bye pass capacitor)
Try a new chip.

MicroKid

[samud]

you have to enable  Watchdog timer  and check out power supply, use a good bypass capacitor

[samad]

thanks all

[SergioFX]

Hi, maybe the power supply varies and the burnout (see avr fuse) halt the program execution.

[mylogin]

check your program when initialize the MCU there are some thing not initialized by your program, it could be in unknown state.  check the fuse bit config.   sometimes reprogram will reset it to a  known state but after a while it is unknown.     Also check the I/O pins circuit.  sometimes the I/O got latched-up problem, when power-on.   setup reset delay feature in the MCU when power-up so it will stay in RESET longer, after all I/O pin is stable then MCU is out of the RESET state.

[samad]

my flash is safe because programmer can read it correctly
the wdt is enabled and ofcourse reset can't solve the problem
i use multilayer and tantal caps with a big elec one
i'm sure that i don't have problem with brown out reset
i'm sure that i don't have any unknown state 
there is no problem with fuse bits
after power on i wait about one second

[freddy]

sometimes avr can't continue its correct working , but
reading it's code from itself & reprograming can solve this problem
i can't understand that how the reprograming can solve it,please help me..
---------------------------
my flash is safe because programmer can read it correctly
the wdt is enabled and ofcourse reset can't solve the problem
i use multilayer and tantal caps with a big elec one
i'm sure that i don't have problem with brown out reset
i'm sure that i don't have any unknown state 
there is no problem with fuse bits
after power on i wait about one second

....but reading it's code from itself & reprograming can solve this problem....

When you do this... usualy the E2Prom are cleared.
I think that's you are using the E2Prom in your application and some writing of
incorrect value make all your problems.

[samad]

my eeprom is write protected(fuse bit..)

[mylogin]

>sometimes avr can't continue its correct working , but
>reading it's code from itself & reprograming can solve this problem
>i can't understand that how the reprograming can solve it,please help me..

try reading it's code from itself  ONLY! & "DO NOT" reprograming,  see if it can solve this problem.
if yes, then it is not the programming problem.  check pins related to programming. (RESET, SCK, SD,..)

[rtm]

Good old practice is to compare checksum of your program flash memory during init.
It will allow to avoid unstable working because of corrupted firmware.
Also it is not so bad idea to clean all ram during init.

[adamhorden]

Have you got any brown out circuits or similar? Is the supply clean? Hvae you looked at the supply rails with a scope to see if you can see any glitches around the time the micro locks up?

Adam

[samad]

thanks to all
checksum is the same..
brown out and other reset sourses couldn't help me..
my supply is clean..

[mpas]

And which type of mega AVR you use?

[samad]

atmega32-16pu