65816 Addressing mode: Block Move Negative (backward) -- xyc

 (MVN)
 (3 bytes)  (7 cycles)

    +---------------+------------------+-----------------------+----------+
    |     Cycle     |   Address Bus    |       Data Bus        |Read/Write|
    +---------------+------------------+-----------------------+----------+
    |        +- 1   |  PBR,PC          | Op Code               |    R     |
    |        |  2   |  PBR,PC+1        | Dest. Bank Address    |    R     |
    |        |  3   |  PBR,PC+2        | Source Bank Address   |    R     |
    |   N-2  |  4   |  SBA,X           | Source Data           |    R     |
    |   Byte |  5   |  DBA,Y           | Dest Data             |    W     |
    |   C=2  |  6   |  DBA,Y           | Internal Operation    |    R     |
    |        +- 7   |  DBA,Y           | Internal Operation    |    R     |
    |        +- 1   |  PBR,PC          | Op Code               |    R     |
    |        |  2   |  PBR,PC+1        | Dest. Bank Address    |    R     |
    |   N-1  |  3   |  PBR,PC+2        | Source Bank Address   |    R     |
    |   Byte |  4   |  SBA,X+1         | Source Data           |    R     |
    |   C=1  |  5   |  DBA,Y+1         | Dest Data             |    W     |
    |        |  6   |  DBA,Y+1         | Internal Operation    |    R     |
    |        +- 7   |  DBA,Y+1         | Internal Operation    |    R     |
    |        +- 1   |  PBR,PC          | Op Code               |    R     |
    |        |  2   |  PBR,PC+1        | Dest. Bank Address    |    R     |
    | N Byte |  3   |  PBR,PC+2        | Source Bank Address   |    R     |
    |   Last |  4   |  SBA,X+2         | Source Data           |    R     |
    |   C=0  |  5   |  DBA,Y+2         | Dest Data             |    W     |
    |        |  6   |  DBA,Y+2         | Internal Operation    |    R     |
    |        |  7   |  DBA,Y+2         | Internal Operation    |    R     |
    |        +- 1   |  PBR,PC+3        | New Op Code           |    R     |
    +---------------+------------------+-----------------------+----------+

    See also: Abbreviations

   x = Source Address
   y = Destination
   c = Number of Bytes to move -1
   x,y Increment
   MVN is used when the destination start address is lower (more negative)
   than the source start address.

   FFFFFF
     |  Source End
     |  Dest End
     |  Source Start
     v  Dest Start
   000000