Data Memory Addressing - NEC mPD780344 Series User Manual

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.
Several addressing modes are provided for addressing the memory relevant to the execution of instructions for
the µ PD780344, 780354, 780344Y, and 780354Y 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 (SFR) and general-purpose registers are available for use. The correspondence between the data memory
and the addressing mode is illustrated in Figures 3-4 to 3-6. For details of each addressing mode, see 3.4 Operand
Address Addressing.
Figure 3-4. Correspondence Between Data Memory and Addressing
F F F F H
Special function registers (SFRs)
256 × 8 bits
F F 2 0 H
F F 1 F H
F F 0 0 H
F E F F H
General-purpose
registers 32 × 8 bits
F E E 0 H
F E D F H
Internal high-speed RAM
512 × 8 bits
F E 2 0 H
F E 1 F H
F D 0 0 H
F C F F H
Reserved
F A 2 8 H
F A 2 7 H
LCD display RAM
40 × 8 bits
F A 0 0 H
F 9 F F H
Reserved
F 8 0 0 H
F 7 F F H
Internal expansion RAM
512 × 8 bits
F 6 0 0 H
F 5 F F H
Reserved
6 0 0 0 H
5 F F F H
Internal ROM
24,576 × 8 bits
0 0 0 0 H
Note The area not used as LCD display data can be used as normal RAM.
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CHAPTER 3 CPU ARCHITECTURE
( µ PD780343, 780353, 780343Y, 780353Y)
SFR addressing
Register addressing
Note
User's Manual U15798EJ2V0UD
Short direct
addressing
Direct addressing
Register indirect
addressing
Based addressing
Based indexed
addressing