Coprocessor 15
2-17
MPU Subsystem
Figure 2–3. Format of the CP15 Translation Table Base Register
31
14
13
0
Translation Table Base
UNP/SBZ
Reading from CP15 register 2 returns the pointer to the currently active first-
level translation table in bits 31 – 14 and an unpredictable value in bits 13 – 0.
The CRm and opcode_2 fields are SBZ when reading this register.
Writing to CP15 register 2 updates the pointer to the currently active first-level
translation table from the value in bits 31 – 14 of the written value. Bits 13 – 0
must be written as zero. The CRm and opcode_2 fields are SBZ when writing
to this register.
Figure 2–4. Format of the CP15 Domain Access Control Register
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
D15
D14
D13
D12
D11
D10
D9
D8
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
D7
D6
D5
D4
D3
D2
D1
D0
Reading from CP15 register 3 returns the value of the domain access control
register. The CRm and opcode_2 fields are SBZ when reading this register.
Writing to CP15 register 3 writes the value of the domain access control
register.
The CRm and opcode_2 fields are SBZ when writing to this register.
The domain access control register consists of sixteen two-bit fields, each
defining the access permissions for one of the 16 domains (D15-D0).
Table 2–8 gives more details on the meaning of each field.
Data, instructions, or both can use each of these domains. Two basic kinds of
users are supported: clients and managers.