![](http://datasheet.mmic.net.cn/380000/-PD98501_datasheet_16745028/-PD98501_138.png)
CHAPTER 2 V
R
4120A
138
Preliminary User’s Manual S14767EJ1V0UM00
Figure 2-39. Supervisor Mode Address Space
64-bit mode
32-bit mode
Note
0xDFFF FFFF
0xE000 0000
0xC000 0000
0xBFFF FFFF
0xFFFF FFFF
Address error
0x0000 000F FFFF
0000
FFFF
0xFFFF FFFF FFFF FFFF
suseg
sseg
0x7FFF FFFF
0x0000 0000
0x8000 0000
xsuseg
xsseg
csseg
0x4000 00FF FFFF FFFF
0x4000 0100 0000 0000
0.5 Gbytes with
TLB mapping
Address error
2 Gbytes with
TLB mapping
Address error
0.5 Gbytes with
TLB mapping
Address error
1 Tbyte with
TLB mapping
Address error
1 Tbyte with
TLB mapping
0xFFFF FFFF E000 0000
0xFFFF FFFF DFFF FFFF
0x0000 0010 0000
0x3FFF FFFF FFFF FFFF
0x4000 0000 0000 0000
0x0000 0000 0000 0000
0x0000 00FF FFFF FFFF
0x0000 0100 0000 0000
Note
The V
R
4120A uses 64-bit addresses within it. For 32-bit mode addressing, bit 31 is sign-extended to bits
32 to 63, and the resulting 32 bits are used for addressing. Usually, it is impossible for 32-bit mode
programs to generate invalid addresses. In an operation of base register + offset for addressing, however,
a two's complement overflow may occur, causing an invalid address. Note that the result becomes
undefined. Two factors that can cause a two’s complement follow:
—
When offset bit 15 is 0, base register bit 31 is 0, and bit 31 of the operation “base register + offset” is 1
—
When offset bit 15 is 1, base register bit 31 is 1, and bit 31 of the operation “base register + offset” is 0
Table 2-49. 32-bit and 64-bit Supervisor Mode Segments
Address Bit
Status Register Bit Value
Segment
Address Range
Size
Value
KSU
EXL
ERL
SX
Name
32-bit
A31 = 0
01
0
0
0
suseg
0x0000 0000
to
0x7FFF FFFF
2 Gbytes
(2
31
bytes)
32-bit
A(31:29) = 110
01
0
0
0
sseg
0xC000 0000
to
0xDFFF FFFF
512 Mbytes
(2
29
bytes)
64-bit
A(63:62) = 00
01
0
0
1
xsuseg
0x0000 0000 0000 0000
to
0x0000 00FF FFFF FFFF
1 Tbyte
(2
40
bytes)
64-bit
A(63:62) = 01
01
0
0
1
xsseg
0x4000 0000 0000 0000
to
0x4000 00FF FFFF FFFF
1 Tbyte
(2
40
bytes)
64-bit
A(63:62) = 11
01
0
0
1
csseg
0xFFFF FFFF C000 0000
to
0xFFFF FFFF DFFF FFFF
512 Mbytes
(2
29
bytes)