Chapter 3 Cpu Architecture; Memory Space - NEC 78K0 User Manual

3.1

Memory Space

78K0/KF1 products can each access a 64 KB memory space. Figures 3-1 to 3-5 show the memory maps.
Caution Regardless of the internal memory capacity, the initial values of the internal memory size
switching register (IMS) and internal expansion RAM size switching register (IXS) of all 78K0/KF1
products are fixed (IMS = CFH, IXS = 0CH). Therefore, set the value corresponding to each
product as indicated below.
Table 3-1. Set Values of Internal Memory Size Switching Register (IMS)
µ
PD780143
µ
PD780144
µ
PD780146
µ
PD780148
µ
PD78F0148

CHAPTER 3 CPU ARCHITECTURE

and Internal Expansion RAM Size Switching Register (IXS)
IMS
C6H
C8H
CCH
CFH
Value corresponding to mask ROM version
*
User's Manual U15947EJ2V0UD
IXS
0CH
0AH
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