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Richard Erlacher
02/01/12 19:26
Read: 292 times
Denver, Co
USA


 
#185770 - Please explain what the "power-on glitch" is ...
Responding to: ???'s previous message
First of all, I have to agree with Michael, that you're just inventing excuses for (a) your failure to read and understand the datasheet, and (b) for your apparently complete ignorance of industry practice in this field.

I've been doing things with digital logic, microprocessors, microcontrollers, etc, since the '60's, and used the original 8051 back when it was just a pup, not to mention its predecessors. Every one of these chips starting with the 8048 had much stronger negative-going drive than positive, and that, quite simply, was because of industry convention. Drivers back in the day, were always inverting open-collectors, until considerably later when tristate drivers, which, BTW, were still active-low types, became common. Even those were mostly inverting types, since, back then, one communicated with other devices over a bus, which, then, was often a backplane which, in turn, required receivers on the target boards. Low-side high-current drivers were driven with a positive output only to provide low-going drive to relays, LED cathodes, etc. Current was most commonly limited by resistors at the high-side, and the driver sank the current. As target devices became less power-hungry, the MCU's themselves became capable of driving some of them, hence, relatively high-current-sink low-current-source drivers at the MCU pins.

If you really believe that the PIC-series is a better choice for you, I'd encourage you to use it. I wouldn't waste another moment worrying about the things you don't like in the 805x series.

Having, myself, spent many, Many, MANY hours with oscilloscopes and logic analyzer on various 805x's, I'd be really interested in details about what it is to which you refer as that "power-on-glitch." I'd bet there's another term for it.

RE


List of 34 messages in thread
TopicAuthorDate
Power-On Port Status Problem      Adam Blue      01/30/12 08:42      
   Wrong idea      Per Westermark      01/30/12 08:48      
   you will not      Erik Malund      01/30/12 08:49      
   you are not the only one      Erik Malund      01/30/12 09:18      
   ATMEL be ashamed      Adam Blue      01/30/12 15:05      
      No, YOU should be ashamed...      Kai Klaas      01/30/12 16:15      
      Nonsense!        Andy Neil      01/30/12 16:46      
      PIC Does so      Neil Kurzman      01/30/12 23:08      
         Oh really??      Michael Karas      01/31/12 07:46      
            "Glitch" in the sense of kind of "setback in a plane"?      Kai Klaas      01/31/12 10:19      
   Try These Ideas        Michael Karas      01/30/12 17:21      
   "Glitch"      Adam Blue      02/01/12 13:12      
      what is not “ATMEL true”.      Erik Malund      02/01/12 13:37      
      I think you are making excuses      Erik Malund      02/01/12 13:41      
      Oh, boohoo!        Rob Klein      02/01/12 14:04      
      What a bunch of fatty sausage...      Michael Karas      02/01/12 14:59      
      "very easy problem"      Andy Neil      02/01/12 15:02      
   Power-On Glitch      Adam Blue      02/01/12 15:40      
      Nonsense - again      Andy Neil      02/01/12 16:28      
      Please explain what the "power-on glitch" is ...      Richard Erlacher      02/01/12 19:26      
      Into The Frying Pan        Michael Karas      02/01/12 20:52      
      Power-on problem...      Kai Klaas      02/02/12 05:55      
      You are still blaming the tools      Per Westermark      02/03/12 05:55      
   Design the hardware first.      David Prentice      02/02/12 07:21      
      do not Design the hardware first.      Erik Malund      02/02/12 07:30      
   Power-On Glitch      Adam Blue      02/02/12 15:07      
      that you had the worst possible reset circuit      Erik Malund      02/02/12 15:59      
      RC-reset...      Kai Klaas      02/02/12 17:20      
      Sorry, double post, don't know why...      Kai Klaas      02/02/12 17:21      
         No, you're not the only one      Richard Erlacher      02/02/12 21:12      
      Would I Hire?      Michael Karas      02/02/12 22:44      
         incidentially      Erik Malund      02/03/12 07:09      
   Power On satus Problem      Satish S Munot      02/29/12 10:16      
      echo, echo, echo      Erik Malund      02/29/12 10:30      

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