User's Manual

THE 80286 INSTRUCTION SET
NEG-Two's Complement Negation
Opcode
F6 /3
F7 /3
FLAGS MODIFIED
Instruction
NEG eb
NEG ew
Clocks
2',mem=7
2,mem=7
Overflow, sign, zero, auxiliary carry, parity, carry
FLAGS UNDEFINED
None
OPERATION
Description
Two's complement negate
EA byte
Two's complement negate
EA word
The two's complement of the register or memory operand replaces the old operand value. Likewise,
the operand
is subtracted from zero, and the result is placed in the operand.
The carry flag
is set to 1 except when the input operand is zero, iii which case the carry flag is Cleared
to O.
PROTECTED MODE EXCEPTIONS
#GP(O) if the result is in a non-writable segment. #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 1 J for a word operand at offset OFFFFH.
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