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???
04/01/05 19:12
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#90830 - not as simple, but less table
Responding to: ???'s previous message
How about this for an idea. Use a 4 bit lookup table to reverse a nybble. Lookup eack nybble, and then SWAP the nybbles. Is it this simple or am I missing something?

Yes, that is (probably) faster than pure code, but by no means as fast as the full byte lookup. Flash today is a throwaway commodity and if you do not have 256 bytes to spare, you probably should not do something that require reversals (cheap toys do not).

Erik

List of 36 messages in thread
TopicAuthorDate
Reversing Algorithm            01/01/70 00:00      
   remembered this one            01/01/70 00:00      
      the fastest code in the west            01/01/70 00:00      
         Am I wrong            01/01/70 00:00      
            not as simple, but less table            01/01/70 00:00      
               lookup table            01/01/70 00:00      
                  nope            01/01/70 00:00      
                     swap, the nibble mirror            01/01/70 00:00      
                        nibble-wise?            01/01/70 00:00      
                     nope nope            01/01/70 00:00      
                        noipe, nope, nope            01/01/70 00:00      
                            noipe, nope, nope, nope            01/01/70 00:00      
                              Ok, Ok. Ok, OK            01/01/70 00:00      
                                 max.255 entries - or the tricks :-)            01/01/70 00:00      
                                    the value of verification            01/01/70 00:00      
                  Mirrored tracks            01/01/70 00:00      
                     Why ?            01/01/70 00:00      
                        Working fine            01/01/70 00:00      
                           why you post wrong code ?            01/01/70 00:00      
                              Yes. Code has bug - Peter            01/01/70 00:00      
                                 efficiency            01/01/70 00:00      
                                    Obvious Vs Smart code            01/01/70 00:00      
                                       sorry            01/01/70 00:00      
                                          No offence - only learning            01/01/70 00:00      
   One byte-reversing solution            01/01/70 00:00      
   Byte Bit Reversal            01/01/70 00:00      
      Re: Byte Bit Reversal            01/01/70 00:00      
   Bit Addressing solution!            01/01/70 00:00      
      Hardware?            01/01/70 00:00      
      2 byte of ram or 2 port?            01/01/70 00:00      
   Three ways:            01/01/70 00:00      
      Three (smart) ways            01/01/70 00:00      
      Thanks, Peter, but...            01/01/70 00:00      
         its faster            01/01/70 00:00      
   Topic has been discussed before            01/01/70 00:00      
   You could try a CPLD            01/01/70 00:00      

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