Post by thread:add32 / sub32

ok, let's see if i learned my lesson well. will the sub32 routine work correctly? i also modified the add routine so the answer for both functions is returned in the 'A'. michael ;Given A3,A2,A1,A0 ; B3,B2,B1,B0 ;Returns A = A + B ADD32 movf B0,w ;Low byte addwf A0,f movf B1,w ;Middle low byte btfsc STATUS,C incfsz B1,w addwf A1,f movf B2,w ;Middle high byte btfsc STATUS,C incfsz B2,w addwf A2,f movf B3,w ;High byte btfsc STATUS,C incfsz B3,w addwf A3,f return ;Given A3,A2,A1,A0 ; B3,B2,B1,B0 ;Returns A = A - B SUB32 movf B0,w ;Low byte subwf A0,f movf B1,w ;Middle low byte btfsc STATUS,C incfsz B1,w subwf A1,f movf B2,w ;Middle high byte btfsc STATUS,C incfsz B2,w subwf A2,f movf B3,w ;High byte btfsc STATUS,C incfsz B3,w subwf A3,f return end

Michael Hagberg <spam_OUTPICLISTTakeThisOuTMITVMA.MIT.EDU> wrote: {Quote hidden}> ok, let's see if i learned my lesson well. will the sub32 routine > work correctly? > .... > ;Returns A = A - B > > SUB32 movf B0,w ;Low byte > subwf A0,f > > movf B1,w ;Middle low byte > btfsc STATUS,C > incfsz B1,w > subwf A1,f > > movf B2,w ;Middle high byte > btfsc STATUS,C > incfsz B2,w > subwf A2,f > > movf B3,w ;High byte > btfsc STATUS,C > incfsz B3,w > subwf A3,f > return Michael: No, it won't work... You need to replace all those BTFSC's with BTFSS's. -Andy === Andrew Warren - .....fastfwdKILLspam@spam@ix.netcom.com === Fast Forward Engineering - Vista, California === http://www.geocities.com/SiliconValley/2499