w65c816s Western Design Center, Inc., w65c816s Datasheet - Page 24

• Manufacturer Part Number: w65c816s
• Description: W65c816s 8/16?bit Microprocessor
• Manufacturer: Western Design Center, Inc.

3.5.23 Stack Relative-d,s
With Stack Relative (d,s) addressing the low-order 16 bits of the effective address is formed from the
sum of the second byte of the instruction and the stack pointer. The high-order 8 bits of the effective
address are always zero. The relative offset is an unsigned 8-bit quantity in the range of 0 to 255.
3.5.24 Stack Relative Indirect Indexed-(d,s),y
With Stack Relative Indirect Indexed ((d,s),y) addressing the second byte of the instruction is added to
the Stack Pointer to form a pointer to the low-order 16-bit base address in Bank 0. The Data Bank
Register contains the high-order 8 bits of the base address. The effective address is the sum of the 24-
bit base address and the Y Index Register.
Instruction:
then:
Operand Address:
Instruction:
then
+
Operand Address:
+
Opcode
Opcode
DBR
00
00
+
effective address
base address
offset
offset
effective address
Stack Pointer
Stack Pointer
S + offset
Y Reg
offset
offset
24