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306
CHAPTER 21
µ
PD78F0066
Preliminary User’s Manual U13420EJ2V0UM00
21.1 Memory Size Switching Register
The
µ
PD78F0066 allows users to select the internal memory capacity using the memory size switching register
(IMS) so that the same memory map as that of the
µ
PD780065 with a different size of internal memory capacity can
be achieved.
IMS is set by using an 8-bit memory manipulation instruction.
RESET input sets IMS to CFH.
Caution
The initial value of IMS is CFH (setting prohibited). As the initial program setting, be sure to
set the following values.
µ
PD780065:
CAH
µ
PD78F0066: CCH or a value supporting the Mask ROM version
Figure 21-1. Format of Memory Size Switching Register (IMS)
Address: FFF0H After reset: CFH R/W
Symbol
7
6
5
4
3
2
1
0
IMS
RAM2
RAM1
RAM0
0
ROM3
ROM2
ROM1
ROM0
RAM2
RAM1
RAM0
Internal high-speed RAM capacity selection
1
1
0
1024 bytes
Other than above
Setting prohibited
ROM3
ROM2
ROM1
ROM0
Internal ROM capacity selection
1
0
1
0
40 Kbytes
1
1
0
0
48 Kbytes
Other than above
Setting prohibited
Summary of Contents for mPD780065 Series
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