
The Western Design Center, Inc.
W65C02S Data Sheet
The Western Design Center, Inc. W65C02S Data Sheet
17
4.4
Absolute Indexed with Y a, y
With the Absolute Indexed with Y addressing mode, the Y Index Register is added to the second and third bytes of the
instruction to form the 16-bit effective address.
Byte:
Instruction:
Operand address:
4.5
Absolute Indirect (a)
With the Absolute Indirect addressing mode, the second and third bytes of the instruction form an address to a pointer. This
address mode is only used with the JMP instruction and the Program Counter is loaded with the first and second bytes at this
pointer.
Byte:
Instruction:
Indirect address:
New PC value:
4.6
Accumulator A
With Accumulator addressing the operand is implied as the Accumulator and therefore only a single byte forms the
instruction..
Byte:
Instruction:
Operand:
4.7
Immediate Addressing #
With Immediate Addressing the operand is the second byte of the instruction.
Byte:
Instruction:
Operand:
4.8
Implied i
Implied addressing uses a single byte instruction. The operand is implicitly defined by the instruction.
Byte:
Instruction:
Operand address:
2
1
0
ADH
ADL
ADH
effective address
OpCode
ADL
Y
+
2
1
0
ADH
ADL
ADH
OpCode
ADL
indirect address
2
1
0
OpCode
accumulator
2
1
0
Operand
OpCode
Operand
2
1
0
OpCode
implied