Rohm LAPIS SEMICONDUCTOR ML620Q503, User Manual

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ML620Q503/Q504 User's Manual
Chapter 2 CPU and Memory Space
FEUL620Q504 2–3
2.3 Data Memory Space
The data memory space consists of the segment 0 for the ROM window area, RAM area, and SFR area, the
segments 7 and F for the flash data area, and the segments 1, 8, and 9 for the ROM reference area.
The data memory space is configured by 32K words (64Kbytes) as one segment (data segment).
The ROM window area is a window opened in the ROM area for the ROM area data to be accessed using the
RAM addressing. The same address data in the program memory space can be read through this window.
In the SFR area, the special function registers (SFRs) that control the LSI function block operations are placed.
In the flash data area, the Flash memory is placed which is readable and writable as data area.
For writing to this area, see Chapter 27, "Flash Memory Control".
Note that the flash data area cannot be operated as program memory.
The data memory stores 8-bit data and is specified by 20 bits consisting of higher 4 bits as DSR and lower 16 bits
as addressing specified by each instruction.
Figure 2-3 shows the configuration of the data memory space.
[Note]
The contents of the RAM area are undefined at power-on and system reset. Initialization of this area by
software is required.
DSR:DADR
Data segment 0 Data segment 7
0:0000H
ROM Window
area
7:0000H
7:07FFH
Data flash
area
0:7DFFH 7:0800H
Unused area
0:7F00H
Unused area
0:E7FFH
0:E800H
0:EFFFH
RAM area
0:F000H
SFR area
0:FFFFH 7:FFFFH
8bit 8bit
DSR:DADR
Data segment 8 Data segment F
8:0000H
Code segment 0
Reference area
F:0000H
F:07FFH
Data segment 7
Reference area
F:0800H
Unused area
8:7FFFH
Unused area
8:FFFFH F:FFFFH
8bit 8bit
* Segments 1 to 6 and 9 to E are unused areas.
(a) ML620Q503