NOP             No Operation                         Flags: Not altered

NOP

    NOP performs no action. NOP is a one-byte instruction that affects
    none of the machine context except the instruction pointer.

    This instruction is used for timing purposes, as a place-holder,
    or to force memory alignment.

    NOP is an alias for XCHG AX,AX.


    Opcode      Format
    90          NOP


    Length and timing
    Operands    Bytes   8088    186     286     386     486     Pentium
    -            1       3       3       3       3       1       1   UV