Indexed Addressing (X) - ZiLOG Z8 PLUS User Manual

4-Bit Working
Registers Address
Instruction Example
References
Program Memory
Figure 2-4. Indirect Register Addressing to Program Memory

INDEXED ADDRESSING (X)

The Indexed Addressing Mode is used only by the Load (LD) instruction. An indexed address consists of a
register address offset by the contents of a designated Working Register (the Index). This offset is added to
the register address to obtain the address of the operand. Figure 2-5 illustrates this addressing convention.
Program Memory
dst src
Points to the
Working
OpCode
Register
Pair (Even
Address)
Value Used in
the Instruction
Register File
RP
Register
Pair LSB
Register
Pair MSB
Program
Memory
Operand
.75
P Â
Points to the Origin
of the Working
Register Group
16-Bit Address
Points to Program
Memory