User's Manual

THE 80286 INSTRUCTION SET
DIV -Unsigned Divide
Opcode
F6 /6
F7 /6
FLAGS MODIFIED
None
Instruction
DIVeb
DIVew
FLAGS UNDEFINED
Clocks
14,mem=17
22,mem=25
Overflow, sign, zero, auxiliary carry, parity, carry
OPERATION
Description
Unsigned divide AX by EA byte
Unsigned divide DX:AX by EA word
DIY performs an unsigned divide. The dividend is implicit; only the divisor is given as an operand. If
the source operand is a BYTE operand, divide AX by the byte. The quotient is stored in AL, and the
remainder
is stored in AH. If the source operand is a WORD operand, diyide DX:AX by the word.
The high-order
16 bits of the dividend are kept in DX. The quotient is stored in AX, and the remainder
is stored in DX. Non-integral quotients are truncated towards O. The remainder is always less than the
dividend.
PROTECTED MODE EXCEPTIONS
Interrupt 0 if the quotient is too big to fit in the designated register (AL or AX), or if the divisor is
zero. #GP(O) for an illegal memory operand effective address in the CS, DS, or ES segments; #SS(O)
for an illegal address in the SS segment.
REAL ADDRESS MODE EXCEPTIONS
Interrupt 0 if the quotient is too big to fit in the designated register (AL or AX), or if the divisor is
zero. Interrupt 13 for a word operand at offset OFFFFH.
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