PIC Microcontroller Basic Math Methods

Try the NEW http://www.piclist.com code generator by Nikolai Golovchenko for Multiplication and Division by a constant.

• Add

  • bcd packed 2 digits from Scott Dattalo
  • 24bit binary from Dwayne Reid
  • 32bit binary from Regulus Berdin

• Subtract

  • bcd packed from Scott Dattalo
  • 16bit with borrow from Rudy Wieser

• Increment / Decrement

  • General Purpose from Dmitry Kiryashov
  • Best 16 bit from Scott Dattalo
  • 32 bit and detect zero from Dmitry Kiryashov, Rich Leggitt, Andrew Warren, and Scott Dattalo

• Two's complement / Negate

  • 32 bit (unknown author, please step forward)
  • 8 bit from Andy Warren

• Multiply

  • 8x8 bit from Andrew Warren
  • 8x8 bit from unknown author (please step forward)
  • 8x8 bit from Scott Dattalo with small correction by Dmitry Kiryashov
  • 16x16 bit macro from Bob Fehrenbach, Scott Dattalo
  • 16x16 bit From Clyde Smith-Stubbs of HI-TECH software
  • 24x8 bit from Byron A Jeff
  • Binary Multiplication by a Constant
  • Tutorial
  • Multiplication and/or division by a Constant See: The PICList code generator
  • See also:
    • http://www.iversoft.com/piclist/9802/0021.shtml
    • http://www.myke.com/PICMicro/16bit.htm

• Divide

  • 8 bit by 8bit to 24bit floating point AN575 format from Nikolai Golovchenko
  • 16 bits by 8 from Lou Zher
  • 24 bits by 16 from Nikolai Golovchenko
  • 24 bits by 16 from Andy David
  • 24 bits by 24 from Tony Nixon
  • Binary Division by a Constant
  • Multiplication and/or division by a Constant See: The PICList code generator
  • see also
    • http://home.netcom.com/~fastfwd/answers.html#PIC00094 from Andrew Warren: 16-bit by 8
    • http://home.netcom.com/~fastfwd/answers.html#PIC00064 from Andrew Warren: 8-bit by 4 PIC16C5x
    • http://www.myke.com/PICMicro/16bit.htm 16 bit by 8
    • http://www.dontronics.com/see.html#division 16 bit by 8

• Scale

  • 8 bit to a percentage from Scott Dattalo with optional precision increase from Nikolai Golovchenko
  • 8 bit to a percentage fast from Jason Harper
  • 8 bit to a percentage accurate from Dmitry Kiryashov

• Square

  • 10 bits by John Payson
  • 4 and 8 bits http://www.infosite.com/~jkeyzer/piclist/1999/Mar/2854.html

• Square Root

  • 32 bit integer by Andy David and Scott Dattalo
  • 24 bit floating point by Nikolai Golovchenko . See also IEEE<>Microchip format conversion
  • 24 bit integer by Andy David and Scott Dattalo
  • 16 bit successive approximation by Andy David
  • 12 bit by Nikolai Golovchenko
  • 8 bit by Nikolai Golovchenko
  • 8 bit fast by Nikolai Golovchenko
  • 8 bit small and fast by Nikolai Golovchenko idea from Scott Dattalo tweak by Dmitry Kiryashov
  • see also:
    • http://www.dattalo.com/technical/software/pic/picsqrt.html
    • http://www.dattalo.com/technical/theory/sqrt.html

see also:

• http://www.markworld.com/microtools.html excellent math (Generate 8 or 16 bit PIC code to evaluate an infix expression. Analyze an IEEE floating point number) and servos
• http://www.microchip.com Math Library Application Notes AN575 Floating Point and AN617 Fixed Point
• http://ndsl226.dnvr.uswest.net/cgi-bin/tl.exe/AERC/Poscalc/math1h.asm 64-bit floating point library
• http://ndsl226.dnvr.uswest.net/cgi-bin/tl.exe/AERC/Poscalc/ SIN, COS, SQRT, etc., routines