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Per Westermark
02/03/12 05:55
Read: 438 times
Sweden


 
#185794 - You are still blaming the tools
Responding to: ???'s previous message
Adam Blue said:
To say again; Low-Active design is not secure for that kind of circuits.

You have to tell that to a number of companies where I have supplied high-security devices. Some who have been sent through specific certification processes because of the humans afety requirements.

And yes - several of them are using Atmel AVR or ARM chips. So despite not being 8051 chips with the 8051 legacy of a weak pull-up, they still use active low signals to activate relays our outputs.

Only a processor with specific programmable "fuses" would be able to descide state of a GPIO pin directly on power up, while the processor is still in the reset state.

If a processor pin is floating (high-impedance input or with a weak internal pull-up or pull-down), then you can use an external resistor to force the signal to VCC or GND. That would result in the signal holding whatever state you want until the application gets into control, and forces the pin to a given state.

If designing hardware with a processor that can not force a pin high, then it's 100% the hw designers task to make sure that the external logic is designed in a way that this doesn't result in any problems. In this case, you seem to have gone for a hw design that does not fulfill this requirement. It does not represent an error with the processor, but an error in the understanding of the requirements. The more you show your anger, the more you tell the world how you failed to understand the used hardware components. So all the blame is actually reflecting back onto you. That should be a good reason why you should consider stopping your blaming of the processor and instead starts to do the smart thing.

8051 chips exists in fire alarms, pacemakers, strong radiation cannons, ... What important product do you work with that have a higher security requirement than that?

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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