LDY                   LDY Load index Y with memory                    LDY
                                                        N Z C I D V
  Operation:  M -> Y                                    / / . . . .
                                 (Ref: 7.1)
  +----------------+-----------------------+---------+---------+----------+
  | Addressing Mode| Assembly Language Form| OP CODE |No. Bytes|No. Cycles|
  +----------------+-----------------------+---------+---------+----------+
  |  Immediate     |   LDY #$FF            |   $A0   |    2    |    2     |
  |  Zero Page     |   LDY $FF             |   $A4   |    2    |    3     |
  |  Zero Page,X   |   LDY $FF,X           |   $B4   |    2    |    4     |
  |  Absolute      |   LDY $FFFF           |   $AC   |    3    |    4     |
  |  Absolute,X    |   LDY $FFFF,X         |   $BC   |    3    |    4*    |
  +----------------+-----------------------+---------+---------+----------+
  * Add 1 when page boundary is crossed.