Data Memory Addressing - NEC switch User Manual

3.1.4 Data memory addressing

The µ PD789800 Subseries provides a variety of addressing modes which take account of memory manipulability,
etc. Especially at addresses corresponding to data memory area (FE00H to FFFFH), particular addressing modes
are possible to meet the functions of the special function registers (SFR) and general-purpose registers. Figures 3-3
and 3-4 show the data memory addressing modes.
FFFFH
Special function registers (SFR)
FF20H
FF1FH
FF00H
FEFFH
Internal high-speed RAM
FE20H
FE1FH
FE00H
FDFFH
2000H
1FFFH
0000H
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CHAPTER 3 CPU ARCHITECTURE
Figure 3-3. Data Memory Addressing ( µ µ µ µ PD789800)
SFR addressing
256 × 8 bits
256 × 8 bits
Reserved
Internal ROM
8,192 × 8 bits
User's Manual U12978EJ3V0UD
Short direct
addressing
Direct addressing
Register indirect
addressing
Based addressing