UPD78F0988AGC-8BS Renesas Electronics America, UPD78F0988AGC-8BS Datasheet - Page 308

• Manufacturer Part Number: UPD78F0988AGC-8BS
• Manufacturer: Renesas Electronics America

Specifications of UPD78F0988AGC-8BS

• Lead Free Status / Rohs Status: Supplier Unconfirmed

18.1 Internal Memory Size Switching Register
switching register (IMS). By setting IMS, the internal memory of the PD78F0988 can be mapped identically to that
of a mask ROM version.
306
For the PD78F0988A, it is possible to select the capacity of the internal memory using the internal memory size
IMS is set by an 8-bit memory manipulation instruction.
RESET input sets this register to CFH.
The values set to IMS in order to obtain the same memory map as mask ROM versions are shown in Table 18-2.
Caution When mask ROM versions are used, IMS should be set to the values shown in Table 18-2. The
Symbol
IMS
RAM2 RAM1 RAM0
7
setting value for the PD780988 is CFH, so it is not necessary to change the initial value.
6
5
Table 18-2. Set Values of Memory Size Switching Register
Figure 18-1. Format of Memory Size Switching Register
4
0
Applicable Mask ROM Versions
PD780982
PD780983
PD780984
PD780986
PD780988
ROM3 ROM2 ROM1 ROM0
3
CHAPTER 18
User’s Manual U13029EJ7V1UD
2
1
0
PD78F0988A
ROM3 ROM2
RAM2 RAM1
Other than above
Other than above
0
0
1
1
1
1
Set Value of IMS
Address
FFF0H
1
1
0
1
1
1
CCH
C4H
C6H
C8H
CFH
ROM1 ROM0
RAM0
0
1
0
0
1
0
After reset
CFH
Internal high-speed RAM capacity selection
1024 bytes
Setting prohibited
0
0
0
0
1
Internal ROM capacity selection
16 KB
24 KB
32 KB
48 KB
60 KB
Setting prohibited
R/W
R/W