6510/65816 Addressing mode: Zeropage/Direct Indexed (R-M-W) -- d,x

 (ASL,DCP,DEC,INC,ISB,LSR,RLA,ROL,ROR,RRA,SLO,SRE)
 (2 bytes)  (6,7,8 and 9 cycles)

    +---------------+------------------+-----------------------+----------+
    |     Cycle     |   Address Bus    |       Data Bus        |Read/Write|
    +---------------+------------------+-----------------------+----------+
    |           1   |  PBR,PC          | Op Code               |    R     |
    |           2   |  PBR,PC+1        | Direct Offset         |    R     |
    |       (2) 2a  |  PBR,PC+1        | Internal Operation    |    R     |
    |           3   |  PBR,PC+1        | Internal Operation    |    R     |
    |           4   |  0,D+DO+X        | Data Low              |    R     |
    |       (1) 4a  |  0,D+DO+X+1      | Data High             |    R     |
    |   (12)(3) 5   |  0,D+DO+X+1      | Internal Operation    |    R     |
    |       (1) 6a  |  0,D+DO+X+1      | Data High             |    W     |
    |           6   |  0,D+DO+X        | Data Low              |    W     |
    +---------------+------------------+-----------------------+----------+
    (1) Add 1 cycle for M=0 or X=0 (i.e. 16 bit data).
    (2) Add 1 cycle for direct register low (DL) not equal 0.
    (3) Special case for aborting instruction. This is the last cycle which
        may be aborted or the Status, PBR or DBR registers will be updated.
   (12) Unmodified Data Low is written back to memory in 6502 emulation
        mode (E=1).

    See also: Abbreviations