UPD78F4218AGF-3BA Renesas Electronics America, UPD78F4218AGF-3BA Datasheet - Page 20

• Manufacturer Part Number: UPD78F4218AGF-3BA
• Manufacturer: Renesas Electronics America

Specifications of UPD78F4218AGF-3BA

• Lead Free Status / Rohs Status: Supplier Unconfirmed

5. INTERNAL MEMORY SIZE SWITCHING REGISTER (IMS)
By setting this register, the internal memory of the µ PD78F4218AY can be mapped identically to that of a mask ROM
version with a different internal memory (ROM and RAM) capacity.
versions.
20
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 FFH.
(1) µ µ µ µ PD78F4216A, 78F4216AY
Caution IMS is not provided on the mask ROM versions ( µ µ µ µ PD784214A, 784215A, 784216A, µ µ µ µ PD784214AY,
Table 5-1 shows the IMS setting values to make the memory mapping the same as that of the mask ROM
Address: 0FFFCH
IMS
784215AY, and 784216AY).
µ PD784214A, 784214AY
µ PD784215A, 784215AY
µ PD784216A, 784216AY
ROM1
RAM1
Table 5-1. Setting Value of Internal Memory Size Switching Register (IMS)
0
0
1
1
0
0
1
1
7
1
Figure 5-1. Internal Memory Size Switching Register (IMS) Format
Target Mask ROM Version
6
1
ROM0
RAM0
After reset: FFH
0
1
0
1
0
1
0
1
ROM1
µ µ µ µ PD78F4216A, 78F4218A, 78F4216AY, 78F4218AY
5
48 KB
64 KB
96 KB
128 KB
3,072 bytes
4,608 bytes
6,114 bytes
7,680 bytes
Data Sheet U14125EJ3V0DS
ROM0
4
W
Peripheral RAM capacity selection
Internal ROM capacity selection
3
1
ECH
FDH
FFH
2
1
IMS Setting Value
RAM1
1
RAM0
0