RM7000B-450T PMC-Sierra, Inc., RM7000B-450T Datasheet - Page 19

• Manufacturer Part Number: RM7000B-450T
• Description: Microprocessor, 64-Bit Data Bus, 450MHz Processor, 304-BGA
• Manufacturer: PMC-Sierra, Inc.

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Proprietary and Confidential to PMC-Sierra, Inc and for its Customers’ Internal Use
Document ID: PMC-2010588, Issue 3
Figure 5 CP0 Registers
Virtual to Physical Address Mapping
The RM7000B provides three modes of virtual addressing:
•
•
•
These modes allow system software to provide a secure environment for user processes. Bits in
the CP0 Status register determine which virtual addressing mode is used. In user mode, the
RM7000B provides a single, uniform virtual address space of 256 GB (2 GB in 32-bit mode).
When operating in the kernel mode, four distinct virtual address spaces, totalling 1024 GB (4 GB
in 32-bit mode), are simultaneously available and are differentiated by the high-order bits of the
virtual address.
The RM7000B processor also supports a supervisor mode in which the virtual address space is
256.5 GB (2.5 GB in 32-bit mode), divided into three regions based on the high-order bits of the
virtual address. Figure 6 shows the address space layout for 32-bit operations.
LLAddr
user mode
kernel mode
supervisor mode
17*
47/63
0
PageMask
EntryHi
TagLo
10*
28*
5*
(entries protected
from TLBWR)
Used for memory
management
TLB
EntryLo0
EntryLo1
2*
3*
TagHi
29*
RM7000B™ Microprocessor with On-Chip Secondary Cache Data Sheet
Random
* Register number
Config
Wired
Index
PRId
Info
15*
16*
7*
0*
1*
6*
Context
Watch2
Status
Count
EPC
ECC
12*
14*
19*
26*
4*
9*
Used for exception
BadVAddr
CacheErr
ErrorEPC
processing
Compare
XContext
Watch1
Cause
11*
13*
18*
20*
27*
30*
8*
Perf Ctr Cntrl
Perf Counter
Watch Mask
25*
22*
24*
Control Space Registers
Imp Error 1
Imp Error 2
IntControl
Preliminary
IPLLO
IPLHI
18*
19*
20*
26*
27*
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