upd78p058f Renesas Electronics Corporation., upd78p058f Datasheet - Page 22

• Manufacturer Part Number: upd78p058f
• Description: Mos Intergrated Circuit, 8-bit Single-chip Microcontroller
• Manufacturer: Renesas Electronics Corporation.

22
4. INTERNAL EXPANSION RAM SIZE SWITCHING REGISTER (IXS)
size switching register (IXS), it is possible to get the same memory mapping as that of a mask ROM version having
different internal expansion RAM.
Symbol
IXS
versions.
Remark Even if a PD78P058F program that includes "MOV IXS, #0CH" is implemented on the PD78056F, its
This is a register to set the internal expansion RAM capacity by software. By setting this internal expansion RAM
The IXS register is set with an 8-bit memory manipulation instruction.
RESET input sets IXS to 0AH.
Table 4-1 shows the setting values of IXS which make the memory mapping the same as that of the mask ROM
operation will not be affected.
7
0
Table 4-1. Internal Expansion RAM Size Switching Register Setting Values
6
0
Figure 4-1. Internal Expansion RAM Size Switching Register Format
5
0
Target Mask ROM Version
4
0
IXRAM3 IXRAM2 IXRAM1 IXRAM0
PD78056F
PD78058F
3
2
1
IXRAM3 IXRAM2 IXRAM1 IXRAM0
Others
IXS Setting Value
1
1
0
0CH
0AH
1
0
Address
FFF4H
0
1
After Reset
0
0
0AH
Expansion RAM Capacity
0 byte
1024 bytes
Setting prohibited
Selection of Internal
PD78P058F
R/W
W