MVN                      MVN Block Move Negative                       MVN

 65816 only!
                                                        N V M X D I C Z
  Operation:                                            . . . . . . . .

  +----------------+-----------------------+---------+---------+----------+
  | Addressing Mode| Assembly Language Form| OP CODE |No. Bytes|No. Cycles|
  +----------------+-----------------------+---------+---------+----------+
  | Block          |   MVN $FF,$FF         |   $54   |    3    |  7/byte  |
  +----------------+-----------------------+---------+---------+----------+
   X-Register = Source Address
   Y-Register = Destination Address
   Accumulator = Number of Bytes to move -1
   $FF,$FF = Source Bank, Destination Bank

   Attention: Some Assemblers exchange those Bank-Bytes!
   Keep also in mind that the Data-Bank-Register may be changed by MVN!

   MVN is used when the destination start address is lower (more negative)
   than the source start address.