division algorithm - Electronic Circuits Projects Diagrams Free

finst · 19th December 2003, 04:50 AM

anyone can help me

i need 8bit and 16bit division algorithm and program code for pic microcontroller

thanks

TheAnimus · 19th December 2003, 08:06 PM

Easy think shift instructions.

When you use a RRF (Rotate Right File) the extra bit is deumped in the carry.
ie:

Code:

div2 macro upperbyte, lowerbyte
RRF  upperbyte,F
RRF lowerbyte,F
endm
; This macro will divide the two params by 2.
; so you could div by 8, by calling that 4 times,
div8 macro upperbyte, lowerbyte
div2 upperbyte, lowerbyte
div2 upperbyte, lowerbyte
div2 upperbyte, lowerbyte
div2 upperbyte, lowerbyte
endm
; And once again to get a div by 16, call div 8 twice
div16 macro upperbyte, lowerbyte
div8 upperbyte, lowerbyte
div8 upperbyte, lowerbyte
endm

Of course this is a bit ugly, you should probably save program space by using a loop (DECFSZ or somthing)

**Nigel Goodwin** · 19th December 2003, 10:17 PM

Quote:

Originally Posted by finst

anyone can help me

i need 8bit and 16bit division algorithm and program code for pic microcontroller

thanks

If you look on the PICLIST at http://www.piclist.com there are various maths routines you can download.

TheAnimus · 20th December 2003, 12:39 AM

hehehe it changed shift too bleep

sh!ft is a bad word !

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19th December 2003, 04:50 AM	(permalink)
finst	division algorithm anyone can help me i need 8bit and 16bit division algorithm and program code for pic microcontroller thanks

20th December 2003, 12:39 AM	(permalink)
TheAnimus	hehehe it changed shift too bleep sh!ft is a bad word !