How can I Divide a Binary Number,
Exp: 72/12 & 100/5,
the Answers need to be in Binary...
Exp: 72/12 & 100/5,
the Answers need to be in Binary...
To you want to do this by hand, with a digital circuit, or with a microprocessor?How can I Divide a Binary Number,
Exp: 72/12 & 100/5,
the Answers need to be in Binary...
My son has this problem for Homework, I don't know how to solve it....To you want to do this by hand, with a digital circuit, or with a microprocessor?
Could you show how the homework was stated?My son has this problem for Homework, I don't know how to solve it....
Last time I checked; binary division was done by shifting the whole byte/word one (or more) places sideways.How can I Divide a Binary Number,
Exp: 72/12 & 100/5,
the Answers need to be in Binary...
Being a bit flash - I have a couple of calculators that work in various number bases.Most any windows PC should have a calculator program. If you hunt thru the menu you will find a scientific calculator, and that can be set to work in binary. You can even change modes to do a conversion, or enter 7 in decimal, change to binary and get 111.
The problem should be done on paper using old fahioned long division but this can help you check each step.
Totally wrong.The first thing you need to do is convert the number to binary.
So 72 would be 1001000.
then to divided by 12 you would first divide the number by 4 and then by 3.
To divide by 4 you would shift the number 2 bits to the right. So 1001000 becomes 10010(18).
Then to divide by 3 you would divide by 2 and then subtract binary 3. Dividing by 2 again 10010 becomes 1001(9). Then subtracting 11(3) 1001 becomes 110 or 6.
To divide 100 by 5 you would divide by 4 by shifting the number 2 bits to the right and then subtract binary 5.
So dividing by 4 1100100(100) becomes 11001(25) and then subtracting 101(5) 11001 becomes 10100 or 20.
Do the math in decimal then convert the answer ti binary,How can I Divide a Binary Number,
Exp: 72/12 & 100/5,
the Answers need to be in Binary...
Not that it matters wrt to this thread, but division doesn't take all that much code. Here's an old 48 bit/24 bit routine I have lying around. It's be smaller for 16/8.As long as this thread left the tracks long ago...
Once I had one rather short program to fit in a tiny micro controller with but one simple division to perform, something like a 16 bit number divided by an 8 bit, both unsigned. When using a C compiler I found that adding the one division made the program just large enough not to fit in my device. I had to use that device for many other reasons.
The work around was to do division by subtraction, literally count how many times I could subtract B from A and still get a positive result.
I had plenty of time to accomplish this task so a simple way worked out just fine.
;*************************************
;** DIV48x24 -- 48bit / 24 bit **
;** OPER15:10 = PROD5:0 / OPER02:00 **
;*************************************
div48x24
movlf bitcnt,25 ;set 24 bit division
clrquo clrf oper10
clrf oper11
clrf oper12
clrf oper13
movfw oper00 ;make sure divisor is not zero (will hang)
iorwf oper01,w
iorwf oper02,w
bz normal ;do fake div without normalizing
clrc
nordom bbs oper02,7,0,normal
rlcf oper00,f
rlcf oper01,f
rlcf oper02,f
incf bitcnt,f
bra nordom
normal clrf divhi
divlp movfw oper00
subwf prod3,w
movwf divtmp0
movfw oper01
subwfb prod4,w
movwf divtmp1
movfw oper02
subwfb prod5,w
movwf divtmp2
clrw
subwfb divhi,w
bm divneg
movwf divhi
movff divtmp2,prod5
movff divtmp1,prod4
movff divtmp0,prod3
divneg rlcf oper10,f
rlcf oper11,f
rlcf oper12,f
rlcf oper13,f
rlcf oper14,f
rlcf oper15,f
rlcf prod0,f
rlcf prod1,f
rlcf prod2,f
rlcf prod3,f
rlcf prod4,f
rlcf prod5,f
rlcf divhi,f
djnz bitcnt,divlp
return
Hola JohnAre you asking about integer division, or do you need an expression for the remainder? Is this purely academic or do you need to write a program?
For "human" binary division, here is a worked example: http://www.exploringbinary.com/binary-division/
For programming, I was intrigued by this discussion of an algorithm for integer multiplication and division attributed Kenyans (and others): http://www.piclist.com/techref/method/math/muldiv.htm
Scan down to the section on novel methods.
John
Assembly
;DIV 216U KENYAN.ASM
DIV_3216U_KEN ;unsigned 32/16-bit values division (KENYAN)
;Agustin T. Ferrari Nicolay - Buenos Aires - April 2007
;Algorithm implemented:
;Given DIVIDEND and DIVISOR, initialize QUOTIENT =0 and INDEX_DSOR =0
;Duplicate DIVISOR repeatedly. Increase PNTR_DSOR every time DIVISOR is doubled
;Repeat doubling to get a DSOR equal to, or the closest below DIVIDEND.
;Substract the highest DSOR from DIVIDEND setting b0 of QUOTIENT.
;Shift QUOTIENT to left and decrement PNTR_DSOR.
;Succesively try to substract from the resulting remainder above, every DIVISOR
;value, down in the list.
;For every possible substraction, keep setting b0 of QUOTIENT and shifting it
;to left. If not possible, just shift QUOTIENT to the left.
;In any case, always decrement PNTR_DSOR.
;Once finished (PNTR_DSOR again =0), the remainder is the result of the last
;substraction. QUOTIENT in the corresponding register.
;To call the routine:
;dividend in DEND_3:0 (max val H'FFFE 0001' = H'FFFF' * H'FFFF' =4.294.836.225)
;divisor in DSOR_1:0 (max value H'FFFF' =65.535) - DSOR_3:2 used internally in
;the routine
;User to ensure being within range or if division by zero is attempted.
;The routine gives:
;Result of DEND_3:DEND_0 / DSOR_1:DSOR_0 => QUOT_H:QUOT_L.
;Remainder in DEND_3:0
CLRF DSOR_3
CLRF DSOR_2
CLRF QUOT_H
CLRF QUOT_L
CLRF PNTR_DSOR
DIV_3216U_KEN_INC_DSOR_LOOP
BCF STATUS,C ;ensure b0 of DSOR_0 is clear after the shifting
RLCF DSOR_0,F ;DSOR =DSOR*2
RLCF DSOR_1,F
RLCF DSOR_2,F
RLCF DSOR_3,F
INCF PNTR_DSOR,F
MOVF DSOR_3,W
SUBWF DEND_3,W
BNZ CHKIF_DSOR3_GT_DEND3
MOVF DSOR_2,W
SUBWF DEND_2,W
BNZ CHKIF_DSOR2_GT_DEND2
MOVF DSOR_1,W
SUBWF DEND_1,W
BNZ CHKIF_DSOR1_GT_DEND1
MOVF DSOR_0,W
SUBWF DEND_0,W
BC DIV_3216U_KEN_INC_DSOR_LOOP
DIV_3216U_KEN_SUBST_DSOR_LOOP
TSTFSZ PNTR_DSOR
BRA DIV_3216U_KEN_DECR_PNTR
RETURN
DIV_3216U_KEN_DECR_PNTR
DECF PNTR_DSOR ;we look down in the list of double DSOR values
BCF STATUS,C ;ensure b0 of QUOT_L is clear after shifting
RLCF QUOT_L,F ;shift QUOT to the left to have it ready
RLCF QUOT_H,F ;for next substraction
BCF STATUS,C ;ensure b7 of DSOR_3 is clear after shifting
RRCF DSOR_3,F ;shift DSOR
RRCF DSOR_2,F ;to the right
RRCF DSOR_1,F ;to get
RRCF DSOR_0,F ;DSOR =DSOR/2
MOVF DSOR_3,W
SUBWF DEND_3,W
BNZ CHKIF_DSOR3_LT_DEND3
MOVF DSOR_2,W
SUBWF DEND_2,W
BNZ CHKIF_DSOR2_LT_DEND2
MOVF DSOR_1,W
SUBWF DEND_1,W
BNZ CHKIF_DSOR3_LT_DEND3
MOVF DSOR_0,W
SUBWF DEND_0,W
BNC DIV_3216U_KEN_SUBST_DSOR_LOOP
DIV_3216U_KEN_SUBST_DSOR ;substract DSOR_3:0 from DEND_3:0
MOVF DSOR_0,W ;LSB, borrow
SUBWF DEND_0,F ;is NOT used
MOVF DSOR_1,W ;borrow
SUBWFB DEND_1,F ;IS used
MOVF DSOR_2,W ;borrow
SUBWFB DEND_2,F ;IS used
MOVF DSOR_3,W ;borrow
SUBWFB DEND_3,F ;IS used
BSF QUOT_L,0 ;flag "a valid substraction from dividend occurred"
BRA DIV_3216U_KEN_SUBST_DSOR_LOOP
CHKIF_DSOR3_GT_DEND3
BNC DIV_3216U_KEN_SUBST_DSOR_LOOP
BRA DIV_3216U_KEN_INC_DSOR_LOOP
CHKIF_DSOR2_GT_DEND2
BNC DIV_3216U_KEN_SUBST_DSOR_LOOP
BRA DIV_3216U_KEN_INC_DSOR_LOOP
CHKIF_DSOR1_GT_DEND1
BNC DIV_3216U_KEN_SUBST_DSOR_LOOP
BRA DIV_3216U_KEN_INC_DSOR_LOOP
CHKIF_DSOR3_LT_DEND3
BC DIV_3216U_KEN_SUBST_DSOR
BRA DIV_3216U_KEN_SUBST_DSOR_LOOP
CHKIF_DSOR2_LT_DEND2
BC DIV_3216U_KEN_SUBST_DSOR
BRA DIV_3216U_KEN_SUBST_DSOR_LOOP
CHKIF_DSOR1_LT_DEND1
BC DIV_3216U_KEN_SUBST_DSOR
BRA DIV_3216U_KEN_SUBST_DSOR_LOOP
by Luke James
by Gary Elinoff