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???
04/15/05 15:53
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#91661 - ... probably impossible in 15 cycles
Responding to: ???'s previous message
Prahlad,
less than 15 Instruction cycles.
I did not actually try, but I doubt you will be able to get so little even with table lookup (remember, this is 3x lookup, so you need 3x mov acc,r0; movc @a+dptr; mov rx,a; and this alone is 12 cycles, and you need also set up dptr 3 times, based on r1...).

On the other hand, is the remainder of the code so tight that you cannot find 15 cycles to spare there?

Jan Waclawek


List of 66 messages in thread
TopicAuthorDate
Fast Square.            01/01/70 00:00      
   Square dancing            01/01/70 00:00      
      table lookup???            01/01/70 00:00      
   code & algorithm            01/01/70 00:00      
      16*16 bit is slower than what I want.            01/01/70 00:00      
         How fast?            01/01/70 00:00      
            Re: How Fast            01/01/70 00:00      
               ... probably impossible in 15 cycles            01/01/70 00:00      
                  why cycles ?            01/01/70 00:00      
                     Re: Microseconds            01/01/70 00:00      
                  table lookup            01/01/70 00:00      
   Natsemi appnote or CORDIC            01/01/70 00:00      
      Natsemi link to appnote            01/01/70 00:00      
   (a+b)^2=a^2+2*a*b+b^2            01/01/70 00:00      
      Thats Slow.            01/01/70 00:00      
         faster need hardware            01/01/70 00:00      
         How fast do you need?            01/01/70 00:00      
            Re: How Fast.            01/01/70 00:00      
               Just?            01/01/70 00:00      
                  Incorrect            01/01/70 00:00      
                     Correct?            01/01/70 00:00      
                        Whooooopa... Sorry.            01/01/70 00:00      
                           Thanks            01/01/70 00:00      
                        I tried...            01/01/70 00:00      
                  optimum? table driven            01/01/70 00:00      
      Jan metod            01/01/70 00:00      
   Hardware?            01/01/70 00:00      
      CPLD?            01/01/70 00:00      
   SILabs f12x does it in hardware            01/01/70 00:00      
      Re: SiLabs F12x            01/01/70 00:00      
   Price            01/01/70 00:00      
      F12x price            01/01/70 00:00      
         F12x MAC            01/01/70 00:00      
            provided in the datasheet            01/01/70 00:00      
   Just out of interest            01/01/70 00:00      
      clarification            01/01/70 00:00      
      CPLD?            01/01/70 00:00      
         too expensive            01/01/70 00:00      
            Absolute rubbish Oleg            01/01/70 00:00      
               explain            01/01/70 00:00      
               your right            01/01/70 00:00      
            especially for those...            01/01/70 00:00      
               I need to say this....            01/01/70 00:00      
               By the way.....            01/01/70 00:00      
   just a demo            01/01/70 00:00      
      Hang on.            01/01/70 00:00      
   Oh bollocks            01/01/70 00:00      
   Well oleg            01/01/70 00:00      
      Please check my answer.            01/01/70 00:00      
         Here you go            01/01/70 00:00      
            You're having me on.            01/01/70 00:00      
               Pascal?            01/01/70 00:00      
               Pascal?            01/01/70 00:00      
            Why ?            01/01/70 00:00      
               It was changed because,,,            01/01/70 00:00      
               Its because            01/01/70 00:00      
   For Jez            01/01/70 00:00      
      For Michael            01/01/70 00:00      
   simulation            01/01/70 00:00      
   Re: Fast Square            01/01/70 00:00      
   Prahlad, waithing for a conclusion            01/01/70 00:00      
      just an exercise...            01/01/70 00:00      
      Tricky            01/01/70 00:00      
         Jez asked his cat, I asked my sheep            01/01/70 00:00      
      Conclusion.            01/01/70 00:00      
      SPI EEPROM            01/01/70 00:00      

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