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???
11/02/06 14:50
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 		 #127263 - One thing that should not be handled by checksummi
Responding to: ???'s previous message
E(E)PROMS do suffer from "memory loss" on the long run

PALCE16V8
1) not EEprom, but flash
2) one of the first flash based GALs (max 100 reprogrammings)
3) while this part http://download.cypress.com/published...16v8_8.pdf do not state it, I remeber parts from that age listed as having a guaranteed 'memory retention' of only 5 years.

One thing that should not be handled by checksumming but handled by careful planning is that flash is not forever. There used to be a 'minimum retention time' in the datasheets, it seems to have disappeared from many (I doubt that is because it is now 'forever'). Hunting I found one "10-year minimum data retention." for the Philips Rx2s as an example of "flash is not forever". Temperature play a major role in this, I seem to recall some part 'guaranteed' for 100 days at 80C when that info was requested.

Thus an automatic replacement/reprogramming system should be implemented, not "when the checksum fails we will fix it"

Erik

List of 26 messages in thread
TopicAuthorDate
Global Checksum            01/01/70 00:00      
   Checksum of what?            01/01/70 00:00      
      Rom Contents            01/01/70 00:00      
         why checksum???            01/01/70 00:00      
            The OP intended to use CRC-32...            01/01/70 00:00      
            ... but it's a good point otherwise...            01/01/70 00:00      
               timestamp vs crc            01/01/70 00:00      
                  timestamp, serial number, neutral 16 bit checksum            01/01/70 00:00      
                  who said 'automatic' and yes I have            01/01/70 00:00      
                     You didn't, Jan did            01/01/70 00:00      
   A bit of a logical fallasy            01/01/70 00:00      
      not at all... depends on application...            01/01/70 00:00      
      Statistics            01/01/70 00:00      
         ferrite beads            01/01/70 00:00      
            \"legitimate\" uses of checksum            01/01/70 00:00      
               I have seen NO catches by a checksum            01/01/70 00:00      
                  it's not just the matter of "kitchenware"...            01/01/70 00:00      
                     One thing that should not be handled by checksummi            01/01/70 00:00      
                        blah blah            01/01/70 00:00      
                        That's not how I remember it ...            01/01/70 00:00      
                           that was me            01/01/70 00:00      
                  I\'ve got a box that contains a few ...            01/01/70 00:00      
            links to CRC            01/01/70 00:00      
               I still say that crc's and checksums only work            01/01/70 00:00      
                  Most            01/01/70 00:00      
      I'd like to learn more            01/01/70 00:00      

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