Controller reset by software?


Our ADuC842 (8051 family) based prototype has started to behave erratically. We're fairly certain it's a hardware problem, but before building a new print we're trying to rule out software problems. One symptom is random controller resets. Can this be caused by failing software? I'm talking about the effects similar to a complete power cycle, not just the PC being reset to address 0.

Thanks, Walter

Reply to
Walter Smits
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If you remove most of your code and have just a few simple routines, will that still continue to happen? Can you get the absolute code minimum where the problem disappears?


Reply to
Alexei A. Frounze

I think you struck one of their errata already ? Where there is one, there may be others, not yet fully defined. Your first RST issue and the trigger conditions can give clues to writing small, stimulus test codes. The 842 is one of a series, so you could also choose a pin compatible variant, and use that as a HW/SW verify 'second opinion', (even if some aspects of performance relax).


Reply to
Jim Granville

Watchdog Timing?

Reply to
Neil Kurzman

Software errors can give the appearance of random failures but the most common reason for your type of fault is power supply to the chip. Make sure you have all the recommended decoupling.

Reply to

That depends on your hardware. If there's a watchdog timer on your board, all it takes is a solid deadlock between two parts of the system, with interrupts disabled, to trigger it and reset your board.

Hans-Bernhard Broeker (
Even if all the snow were burnt, ashes would remain.
Reply to
Hans-Bernhard Broeker

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