Mips Technologies R4000 - Page 104

Chapter 4
74 MIPS R4000 Microprocessor User's Manual
Figure 4-6 Kernel Mode Address Space
*NOTE: The R4000 uses 64-bit addresses internally. In 32-bit mode,
a valid address must be a 32-bit signed number, where bits 63:32 = bit
31; an invalid address produces an undefined result. In 32-bit mode,
a Kernel-mode program may use 64-bit instructions, but must not
create addresses using base register+offset calculations that produce a
32-bit 2’s-complement overflow; in specific, there are two prohibited
cases:
• offset with bit 15 = 0 and base register with bit 31 = 0, but (base
register+offset) bit 31 = 1
• offset with bit 15 = 1 and base register with bit 31 = 1, but (base
register+offset) bit 31 = 0
Address
error
2 GB
0.5 GB
0.5 GB
Mapped
Mapped
Unmapped
Unmapped
kuseg
kseg0
kseg1
0.5 GB
0.5 GB
Mapped
ksseg
kseg3
Uncached
Cached
xkuseg
ckseg0
ckseg1
xksseg
ckseg3
Mapped
0.5 GB
Mapped
0.5 GB
0.5 GB
Unmapped
Uncached
0.5 GB
Unmapped
Cached
Unmapped
Address
error
cksseg
1 TB
Mapped
xkseg
Mapped
xkphys
32-bit*
64-bit
Address
error
0x FFFF FFFF FFFF FFFF
0x 4000 0100 0000 0000
0x 0000 0000 0000 0000
0x FFFF FFFF E000 0000
0x FFFF FFFF C000 0000
0x 4000 0000 0000 0000
0x 0000 0100 0000 0000
0x 8000 0000 0000 0000
0x C000 0000 0000 0000
0x FFFF FFFF A000 0000
0x FFFF FFFF 8000 0000
0x C000 00FF 8000 0000
0x FFFF FFFF
0x 8000 0000
0x 0000 0000
0x E000 0000
0x C000 0000
0x A000 0000
1 TB
Mapped