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INC -- Increment by 1




Opcode      Instruction        Clocks      Description

FE  /0      INC r/m8                       Increment r/m byte by 1
FF  /0      INC r/m16                      Increment r/m word by 1
FF  /6      INC r/m32                      Increment r/m dword by 1
40 + rw     INC r16                        Increment word register by 1
40 + rd     INC r32                        Increment dword register by 1

Operation




DEST := DEST + 1;

Description

INC adds 1 to the operand. It does not change the carry flag. To affect the carry flag, use the ADD instruction with a second operand of 1.

Flags Affected

OF, SF, ZF, AF, and PF as described in Appendix C

Protected Mode Exceptions

#GP(0) if the operand is in a nonwritable segment; #GP(0) for an illegal memory operand effective address in the CS, DS, ES, FS, or GS segments; #SS(0) for an illegal address in the SS segment; #PF(fault-code) for a page fault

Real Address Mode Exceptions

Interrupt 13 if any part of the operand would lie outside of the effective address space from 0 to 0FFFFH

Virtual 8086 Mode Exceptions

Same exceptions as in Real Address Mode; #PF(fault-code) for a page fault

up: Chapter 17 -- 80386 Instruction Set
prev: IN Input from Port
next: INS/INSB/INSW/INSD Input from Port to String