W65C816S Datasheet, PDF (24/62 Pages) List of Unclassifed Manufacturers – Microprocessor

The Western Design Center, Inc.
W65C816S Data Sheet
Direct Indirect Indexed-(d),y
Direct Indirect Indexed ((d),y) addressing is often referred to as Indirect Y addressing. The second byte of the
instruction is added to the Direct Register (D). The 16-bit content of this memory location is then combined with
the Data Bank register to form a 24-bit base address. The Y Index Register is added to the base address to form
the effective address.
Instruction:
then:
+
+
Operand Address:
OpCode offset
Direct Register
+
offset
00
(direct address)
DBR
base address
Y Reg
effective address
Direct Indirect Long Indexed-[d],y
With Direct Indirect Long Indexed ([d],y) addressing the 24-bit base address is pointed to by the sum of the
second byte of the instruction and the Direct Register. The effective address is this 24-bit base address plus the Y
Index Register.
Instruction:
then
Operand Address:
OpCode offset
Direct Register
+
offset
00
direct address
base address
+
Y Reg
effective address
Direct Indirect Long-[d]
With Direct Indirect Long ([d]) addressing the second byte of the instruction is added to the Direct Register to
form a pointer to the 24-bit effective address.
Instruction:
then:
Operand Address:
OpCode offset
Direct Register
+
offset
00
(direct address)
direct address
The Western Design Center
W65C816S
24