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Jan Waclawek
08/06/07 07:05
Modified:
  08/06/07 07:14

Read: 1541 times
Bratislava
Slovakia


 
#142813 - examples
Responding to: Andy Neil's previous message
Andy Neil said:
I usually find that protocol specifications include examples of how to do their specific CRC(s)...



I found the most useful, when the protocol spec contained also an example of input and output of their CRC calculation (either directly, or indirectly as an example packet). I then play with the mentioned CRC calculator page as long as I obtain the required result, and then reach for one of the solutions I already have pre-cooked and deform it in the required way.

Too often the "example implementation" misses "a few small details", e.g. the init value, or that one extra cycle has to be performed at the end - and only the "core routine" is given (preferrably in some arcane language or pseudolanguage, with constants given in octal...).

I found usually this in protocols covered by some sort of NDA - of course these are not subject to public scrutiny, and too often the author of the protocol is immune to rambling of the poor designer ...

JW


List of 23 messages in thread
TopicAuthorDate
How to create a crc table?      John Myers      08/04/07 01:33      
   simple      Jan Waclawek      08/04/07 07:10      
      RE: simple      John Myers      08/04/07 14:34      
         I said it\'s simple      Jan Waclawek      08/04/07 16:33      
            Thank you      John Myers      08/04/07 17:27      
            Protocols      Andy Neil      08/06/07 06:48      
               examples      Jan Waclawek      08/06/07 07:05      
   Runtime Computed Table??      Michael Karas      08/04/07 08:14      
      RE: Runtime...?      John Myers      08/04/07 15:02      
      table is not necessary      Jan Waclawek      08/04/07 16:41      
         Benchmark      John Myers      08/04/07 17:16      
            I did benchmarks as such on AVR      Michael Karas      08/04/07 18:38      
               Similar findings      Russell Bull      08/04/07 20:05      
                  no beavers that I've tended to!!      Michael Karas      08/04/07 21:50      
               not bitwise....      Jan Waclawek      08/05/07 01:45      
            Better is a strong word      Neil Kurzman      08/05/07 20:19      
               Also comment about SMBus PEC Code...      Michael Karas      08/05/07 20:30      
   The Table      Neil Kurzman      08/06/07 10:19      
   The Nibble Table for Poly 107      Neil Kurzman      08/06/07 10:20      
   The formula      Neil Kurzman      08/06/07 10:22      
   Have you seen this?      Richard Erlacher      08/06/07 17:42      
      Now I have      Neil Kurzman      08/06/07 20:26      
      Yes, that is a Key Document!      Andy Neil      08/07/07 01:45      

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