![](http://datasheet.mmic.net.cn/320000/UPD30102_datasheet_16362875/UPD30102_126.png)
CHAPTER 5 MEMORY MANAGEMENT SYSTEM
126
Table 5-2. 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
A[31] = 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)
(1) suseg (32-bit Supervisor mode, user space)
When SX = 0 in the Status register and the most-significant bit of the virtual address space is set to 0, the suseg
virtual address space is selected; it covers 2 Gbytes (2
address is extended with the contents of the 8-bit ASID field to form a unique virtual address. This mapped
space starts at virtual address 0x0000 0000 and runs through 0x7FFF FFFF.
31
bytes) of the current user address space. The virtual
(2) sseg (32-bit Supervisor mode, supervisor space)
When SX = 0 in the Status register and the three most-significant bits of the virtual address space are 110, the
sseg virtual address space is selected; it covers 512 Mbytes (229 bytes) of the current supervisor virtual address
space. The virtual address is extended with the contents of the 8-bit ASID field to form a unique virtual address.
This mapped space begins at virtual address 0xC000 0000 and runs through 0xDFFF FFFF.
(3) xsuseg (64-bit Supervisor mode, user space)
When SX = 1 in the Status register and bits 63 and 62 of the virtual address space are set to 00, the xsuseg
virtual address space is selected; it covers 1 Tbyte (2
address is extended with the contents of the 8-bit ASID field to form a unique virtual address. This mapped
space starts at virtual address 0x0000 0000 0000 0000 and runs through 0x0000 00FF FFFF FFFF.
40
bytes) of the current user address space. The virtual