[EE]: Reset problems - 8535
Attila Muhi email (remove spam text)
I'm using an LS8535 qfp at 3.3V. I get reset problems from time to time, sometimes when I use the dongle fron STK200, sometimes when the application is running normally with the dongle disconnected.
I have a routine pointed to by the reset vector. It seems like the 8535 jumps to that routine on an external reset only when it wants to, not when I want it to :-<
When it goes wrong, it ends up with :
1) My reset routine not executed
2) PortC all pins high
3) PortB,2 high.
4) Rest of the ports tri-stated
5) clock osc running
If it does like this, I have to make about 15-20 reset pulses before it executes my reset routine. And, after that, the next 10-15 external reset pulses DO execute my vector. Then it is back to (ab)normal again. Of course the rest of the software doesn't work when the 8535 get stuck. However, after one of those successful resets, the software behaves excellent, rersponds to IRQ:s and whatever.
There's a .068 uF cap between /reset and gnd, and a 1k res between /reset and Vcc. Is this a bad idea ?
Any comments are useful !
Attila Muhi - SM4RAN
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