CHAPTER 3 CPU
Preliminary User’s Manual A14874EJ3V0UM
64
3.4.2 RAM area
In 64 MB mode, the area at address 3FFEFFFH and below is reserved as the area for RAM connected to the VDB.
In 256 MB mode, the address at FFFEFFFH and below is reserved.
The size of the RAM area, which can be selected from among 4 KB, 12 KB, 28 KB, and 60 KB, is set according to
the input levels to the IFRA64, IFRA32, and IFRA16 pins.
Table 3-4. RAM Area Size Settings
IFIRA64
IFIRA32
IFIRA16
RAM Area Size
0
0
0
4 KB
0
0
1
12 KB
0
1
Arbitrary
28 KB
1
Arbitrary
Arbitrary
60 KB
Remark
0: low-level input 1: high-level input
Figure 3-10. RAM Area
(a) When 4 KB is selected
RAM area
xFFEFFFH
xFFE000H
(b) When 12 KB is selected
RAM area
xFFEFFFH
xFFC000H
(c) When 28 KB is selected
RAM area
xFFEFFFH
xFF8000H
(d) When 60 KB is selected
RAM area
xFFEFFFH
xFF0000H
Set as follows if the size of the RAM area to be used is other than 4 KB, 12 KB, 28 KB, or 60 KB.