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???
02/02/08 17:59
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 		 #150229 - Why do you believe it's going awry during powerup?
Responding to: ???'s previous message
Did you make any observations that suggest it's happening during power-up?

I've casually observed (on other 805x MCU's) external memory accesses during active RESET during the power-down transient, but never observed it during power-up.

I can't think of a good reason why it couldn't occur during power-up, but I can envision why it would happen during power-down, particularly since the charge-pump necessary to program/corrupt FLASH memory is fully charged at power-down.

It's my belief that, if you can discharge Vcc within a couple of microseconds of shutting off the power (protect your regulators with a diode), you won't have this problem, but that's just a guess, so far.

I'd appreciate any information you've gathered in the course of your observation of this problem.

RE


List of 32 messages in thread
TopicAuthorDate
C8051F340 Flash corruption problem            01/01/70 00:00      
   use an open collector supervisor ana a pullup            01/01/70 00:00      
   No problem on my end            01/01/70 00:00      
      Grant, can you confirm            01/01/70 00:00      
         Not at this time            01/01/70 00:00      
         Yes, it's a 4k7 pullup            01/01/70 00:00      
   Why do you believe it's going awry during powerup?            01/01/70 00:00      
      likelyhoods            01/01/70 00:00      
         This is funny!            01/01/70 00:00      
            statistical probability            01/01/70 00:00      
               So you conclude that the world is flat?            01/01/70 00:00      
                  who on earth in his right mind would do that?            01/01/70 00:00      
                     someone who is curious about RESET.            01/01/70 00:00      
                        8051f12x/f13x            01/01/70 00:00      
                           It's not that simple ...            01/01/70 00:00      
                              I have a paid job            01/01/70 00:00      
                                 Indeed you have            01/01/70 00:00      
                                    if 1 million people get sick ...            01/01/70 00:00      
                                       It ain't necessarily so            01/01/70 00:00      
                                          3 things you did not respond to            01/01/70 00:00      
                                             that's not how it works            01/01/70 00:00      
                                                it his not 'details'            01/01/70 00:00      
                                                   What does "works" mean?            01/01/70 00:00      
   SiLabs view on this issue            01/01/70 00:00      
      re a point            01/01/70 00:00      
         I am reading some interesting discussion            01/01/70 00:00      
            AP, yes, Richard read that all say the same.            01/01/70 00:00      
            That means NO??            01/01/70 00:00      
               HUH?            01/01/70 00:00      
   Qazi Please provide some details            01/01/70 00:00      
   flash corruption or write failure            01/01/70 00:00      
      answer to quiz!            01/01/70 00:00      

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