UPD78F0838 Renesas Electronics Corporation., UPD78F0838 Datasheet - Page 808

• Manufacturer Part Number: UPD78F0838
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

26.2 Internal Expansion RAM Size Switching Register
(IXS).
806
The internal expansion RAM capacity can be selected using the internal expansion RAM size switching register
IXS is set by an 8-bit memory manipulation instruction.
Reset signal generation sets IXS to 0CH.
Caution To set memory size, set IMS and then IXS. Set memory size so that the internal ROM area and
Address: FFF4H
Symbol
IXS
Caution Be sure to set each product to the values shown in Table 26-2 after a reset release.
internal expansion RAM area do not overlap.
Figure 26-2. Format of Internal Expansion RAM Size Switching Register (IXS)
PD78F0836
PD78F0844
PD78F0837
PD78F0845
IXRAM4
Table 26-2. Internal Expansion RAM Size Switching Register Settings
78K0/DE2
7
0
0
0
After reset: 0CH
IXRAM3
Flash Memory Version
6
0
1
1
PD78F0838, 78F0840, 78F0842
PD78F0846, 78F0848
PD78F0839, 78F0841, 78F0843
PD78F0847, 78F0849
Other than above
R/W
Preliminary User’s Manual U19748EJ1V0UD
CHAPTER 26 FLASH MEMORY
IXRAM2
5
0
0
0
78K0/DF2
IXRAM4
IXRAM1
4
1
0
IXRAM3
IXRAM0
3
0
0
0AH
08H
Internal expansion RAM capacity selection
1024 bytes
2048 bytes
Setting prohibited
IXRAM2
IXS Setting
2
IXRAM1
1
IXRAM0
0