CHAPTER 26 FLASH MEMORY
Preliminary User’s Manual U17260EJ3V1UD
560
26.2 Internal Expansion RAM Size Switching Register
The internal expansion RAM capacity can be selected using the internal expansion RAM size switching register
(IXS).
IXS is set by an 8-bit memory manipulation instruction.
Reset signal generation sets IXS to 0CH.
Caution Be sure to set each product to the values shown in Table 26-2 after a reset release.
Figure 26-2. Format of Internal Expansion RAM Size Switching Register (IXS)
Address: FFF4H After reset: 0CH R/W
Symbol 7 6 5 4 3 2 1 0
IXS
0
0
0
IXRAM4 IXRAM3 IXRAM2 IXRAM1 IXRAM0
IXRAM4
IXRAM3
IXRAM2
IXRAM1
IXRAM0
Internal expansion RAM capacity selection
0 1 1 0 0
0
byte
0 1 0 1 0
1024
bytes
0 1 0 0 0
2048
bytes
0 0 1 0 0
4096
bytes
0 0 0 0 0
6144
bytes
Other than above
Setting prohibited
Caution To set memory size, set IMS and then IXS. Set memory size so that the internal ROM area and
internal expansion RAM area do not overlap.
Table 26-2. Internal Expansion RAM Size Switching Register Settings
Flash Memory Versions (78K0/KE2)
IXS Setting
µ
PD78F0531
µ
PD78F0532
µ
PD78F0533
0CH
µ
PD78F0534 0AH
µ
PD78F0535 08H
µ
PD78F0536 04H
µ
PD78F0537, 78F0537D
00H