section 7 - Index of

DIV Divide Interation DIVNote that the divide routine used in the previous example assumes that the signextended56-bit signed fractional dividend is stored in the A accumulator and that the 24-bit signed fractional divisor is stored in the XO register. This routine produces a full 24-bitsigned quotient and a 48-bit signed remainder.This routine may be greatly simplified for the case in which only positive, fractional operandsare used to produce a 24-bit positive quotient and a 48-bit positive remainder, asshown in the following example:1-Quadrant division, 24-bit unsigned quotient, 48-bit unsigned remainderAND #$FE,CCR ;clear carry bit C (quotient sign bit)REP #$18;form a 24-bit quotient and remainderDIV XO,A;form quotient in AO, remainder in A1ADD XO,A;restore remainder in A1Note that this routine assumes that the 56-bit positive, fractional, sign-extended dividendis stored in the A accumulator and that the 24-bit positive, fractional divisor is stored inthe XO register. After execution, the 24-bit positive fractional quotient is stored in the AOregister; the LS 24 bits of the 48-bit positive fractional remainder are stored in the A 1 register.There are many variations possible when choosing a suitable division routine for a givenapplication. The selection of a suitable division routine normally involves specification ofthe following items:1. the number of bits of precision in the dividend;2. the number of bits of precision N in the quotient;3. whether the value of N is fixed or is variable;4. whether the operands are unsigned or signed;5. whether or not the remainder is to be calculated.