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CHAPTER 3 CPU ARCHITECTURE
Preliminary User’s Manual U14581EJ3V0UM00
3.1.4 Data memory addressing
Addressing refers to the method of specifying the address of the instruction to be executed next or the address
of the register or memory relevant to the execution of instructions. The address of an instruction to be executed next
is addressed by the program counter (PC) (for details, see 3.3 Instruction Address Addressing).
Several addressing modes are provided for addressing the memory relevant to the execution of instructions for
the
µ
PD780852 Subseries, based on operability and other considerations. For areas containing data memory in
particular, special addressing methods designed for the functions of special function registers (SFRs) and general-
purpose registers are available for use. Data memory addressing is illustrated in Figures 3-4 to 3-6. For the details
of each addressing mode, see 3.4 Operand Address Addressing.
Figure 3-4. Data Memory Addressing (
µ
PD780851(A))
0000H
General registers
32
×
8 bits
Internal ROM
32,768
×
8 bits
LCD display RAM
20
×
4 bits
Internal expansion RAM
512
×
8 bits
8000H
7FFFH
FA59H
FA58H
FA6DH
FA6CH
FEE0H
FEDFH
FF00H
FEFFH
FFFFH
Internal high-speed RAM
1,024
×
8 bits
Reserved
FB00H
FAFFH
FF20H
FF1FH
FE20H
FE1FH
Special function
registers (SFRs)
256
×
8 bits
SFR addressing
Register addressing
Short direct
addressing
Direct addressing
Register indirect
addressing
Based addressing
Based indexed
addressing
F800H
F7FFH
Reserved
F600H
F5FFH
Reserved
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