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User’s Manual U15798EJ2V0UD
CHAPTER 3 CPU ARCHITECTURE
3.1 Memory Spaces
The
µ
PD780344, 780354, 780344Y, 780354Y Subseries can each access a 64 KB memory space.
Figures 3-1 to 3-3 show the memory maps.
Caution In the case of the internal memory capacity, the initial values of the memory size switching
register (IMS) and internal expansion RAM size switching register (IXS) of all products (
µ
PD780344,
780354, 780344Y, and 780354Y Subseries) are fixed (IMS = CFH, IXS = 0CH). Therefore, set the
value corresponding to each product indicated below.
Set Value of IMS
Set Value of IXS
µ
PD780343, 780353, 780343Y, 780353Y
46H
0BH
µ
PD780344, 780354, 780344Y, 780354Y
48H
µ
PD78F0354, 78F0354Y
C8H or
Value corresponding to mask ROM version