Intel 80286, 80287 manual DIV -Unsigned Divide, DIVeb, DIVew

THE 80286 INSTRUCTION SET

DIV -Unsigned Divide

Opcode		Instruction	Clocks	Description
F6	/6	DIVeb	14,mem=17	Unsigned divide AX by EA byte
F7	/6	DIVew	22,mem=25	Unsigned divide DX:AX by EA word

FLAGS MODIFIED

None

FLAGS UNDEFINED

Overflow, sign, zero, auxiliary carry, parity, carry

OPERATION

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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