UPD78F0034AGK-9ET Renesas Electronics America, UPD78F0034AGK-9ET Datasheet - Page 19

• Manufacturer Part Number: UPD78F0034AGK-9ET
• Manufacturer: Renesas Electronics America

Specifications of UPD78F0034AGK-9ET

• Lead Free Status / Rohs Status: Supplier Unconfirmed

5. MEMORY SIZE SWITCHING REGISTER (IMS)
By setting memory size switching register (IMS), the internal memory of the µ PD78F0034A and 78F0034AY can be
mapped identically to that of a mask ROM version.
IMS
IMS is a register that is set by software and is used to specify a part of the internal memory that is not to be used.
IMS is set with an 8-bit memory manipulation instruction.
RESET input sets IMS to CFH.
Caution The initial value of IMS is setting disabled (CFH). Be sure to set C8H or the value of the target
Table 5-1 shows the IMS set value to make the memory mapping the same as those of mask ROM versions.
RAM2 RAM1 RAM0
7
mask ROM version at the moment of initial setting.
6
5
Table 5-1. Set Value of Memory Size Switching Register
Figure 5-1. Format of Memory Size Switching Register
4
0
ROM3 ROM2 ROM1 ROM0
µ PD780031A, 780031AY
µ PD780032A, 780032AY
µ PD780033A, 780033AY
µ PD780034A, 780034AY
3
Target Mask ROM Versions
2
Data Sheet U14040EJ4V0DS
1
ROM3
RAM2
Other than above
Other than above
0
0
0
0
1
0
1
ROM2
RAM1
0
1
1
0
1
1
Address
FFF0H
ROM1
RAM0
42H
44H
C6H
C8H
1
0
1
0
0
0
IMS Set Value
µ PD78F0034A, 78F0034AY
ROM0
Selection of Internal High-Speed RAM Capacity
Setting prohibited
512 bytes
1,024 bytes
After reset
0
0
0
0
CFH
Selection of Internal ROM Capacity
Setting prohibited
8 KB
16 KB
24 KB
32 KB
R/W
R/W
19