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???
12/21/06 06:35
Modified:
  12/21/06 06:36
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 		 #129877 - How can we rely on that specification?
Responding to: ???'s previous message
It seems risky, to me, to assume that the next part you get from Intersil will do more than the datasheet implies. If they intended to provide parts that really do what you observed, under the test conditions they specify, they'd put that in their datasheet, wouldn't they? Did you measure one output only, or all bits as outputs concurrently?

However, they're not the only current maker of 8255's. One Japanese mfg (can't remember whether it was OKI or Toshiba) makes a 90ns part that puts out close to what you suggest you measured. I'd be interested in this only if each and every output could drive a 150-ohm or 220/330 cable termination, though.

RE


List of 29 messages in thread
TopicAuthorDate
The 8255A is stronger and faster than reported.            01/01/70 00:00      
   The Data Sheet rules            01/01/70 00:00      
      How can we rely on that specification?            01/01/70 00:00      
   Not proven!            01/01/70 00:00      
   who give s hoot what you have 'found'            01/01/70 00:00      
      Data sheets don' rule in reverse engineering            01/01/70 00:00      
         Does that mean...            01/01/70 00:00      
            I'm a chip provider, not a user            01/01/70 00:00      
               then do notstate "The 8255A is stronger and fast"            01/01/70 00:00      
                  8255 statements            01/01/70 00:00      
         They do determine what you have to deliver ...            01/01/70 00:00      
            What I Did            01/01/70 00:00      
               Hmmmm ...            01/01/70 00:00      
                  Measuring output DC parameters            01/01/70 00:00      
                     What did you really test?            01/01/70 00:00      
                        DC measurements            01/01/70 00:00      
                           That's why measurements are quick and automatic            01/01/70 00:00      
                              My paycheck?            01/01/70 00:00      
   No!            01/01/70 00:00      
   How?            01/01/70 00:00      
      Measuring Specs            01/01/70 00:00      
   Population v sample sigma            01/01/70 00:00      
      Should know better            01/01/70 00:00      
         Dangerous extrapolations            01/01/70 00:00      
      The other side of the looking glass            01/01/70 00:00      
   The timing issue was the delay ....            01/01/70 00:00      
      Thanks for the tip            01/01/70 00:00      
      8255            01/01/70 00:00      
         do these two things            01/01/70 00:00      

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