3-697
INSTRUCTION SET REFERENCE
UD2—Undefined Instruction
Description
This instruction generates an invalid opcode. This instruction is provided for software testing to
explicitly generate an invalid opcode. The opcode for this instruction is reserved for this
purpose.
Other than raising the invalid opcode exception, this instruction is the same as the NOP instruc-
tion.
Operation
#UD (* Generates invalid opcode exception *);
Flags Affected
None.
Exceptions (All Operating Modes)
#UD
Instruction is guaranteed to raise an invalid opcode exception in all oper-
ating modes).
Opcode
Instruction
Description
0F 0B
UD2
Raise invalid opcode exception
