W65C02S Datasheet, PDF (17/40 Pages) List of Unclassifed Manufacturers – Microprocessor

The Western Design Center, Inc.
W65C02S Data Sheet
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:
2
ADH
1
ADL
0
OpCode
Operand address:
4.5 Absolute Indirect (a)
ADH
ADL
+
Y
effective address
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:
2
ADH
1
ADL
0
OpCode
Indirect address:
ADH
ADL
New PC value:
indirect address
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:
2
1
0
OpCode
Operand:
4.7 Immediate Addressing #
With Immediate Addressing the operand is the second byte of the instruction.
accumulator
Byte:
Instruction:
2
1
0
Operand OpCode
Operand:
Operand
4.8 Implied i
Implied addressing uses a single byte instruction. The operand is implicitly defined by the instruction.
Byte:
Instruction:
2
1
0
OpCode
Operand address:
implied
The Western Design Center, Inc.
W65C02S Data Sheet
17