Intel 253666-024US User Manual
Page 308

3-262 Vol. 2A
DEC—Decrement by 1
INSTRUCTION SET REFERENCE, A-M
Protected Mode Exceptions
#GP(0)
If the destination operand is located in a non-writable segment.
If a memory operand effective address is outside the CS, DS,
ES, FS, or GS segment limit.
If the DS, ES, FS, or GS register contains a NULL segment
selector.
#SS(0)
If a memory operand effective address is outside the SS
segment limit.
#PF(fault-code)
If a page fault occurs.
#AC(0)
If alignment checking is enabled and an unaligned memory
reference is made while the current privilege level is 3.
#UD
If the LOCK prefix is used but the destination is not a memory
operand.
Real-Address Mode Exceptions
#GP
If a memory operand effective address is outside the CS, DS,
ES, FS, or GS segment limit.
#SS
If a memory operand effective address is outside the SS
segment limit.
#UD
If the LOCK prefix is used but the destination is not a memory
operand.
Virtual-8086 Mode Exceptions
#GP(0)
If a memory operand effective address is outside the CS, DS,
ES, FS, or GS segment limit.
#SS(0)
If a memory operand effective address is outside the SS
segment limit.
#PF(fault-code)
If a page fault occurs.
#AC(0)
If alignment checking is enabled and an unaligned memory
reference is made.
#UD
If the LOCK prefix is used but the destination is not a memory
operand.
Compatibility Mode Exceptions
Same exceptions as in protected mode.
64-Bit Mode Exceptions
#SS(0)
If a memory address referencing the SS segment is in a non-
canonical form.
#GP(0)
If the memory address is in a non-canonical form.
#PF(fault-code)
If a page fault occurs.