Epson ARM720T User Manual

MMU accesses are primarily controlled through the use of domains. There are 16 domains and 

each has a 2-bit field to define access to it. Two types of user are supported, clients and 

managers. The domains are defined in the Domain Access Control Register. Figure 7-13 shows 

how the 32 bits of the register are allocated to define the 16 2-bit domains.

Figure 7-13  Domain Access Control Register format

Table 7-10 defines how the bits within each domain are interpreted to specify the access 

permissions.

Table 7-10  Interpreting access control bits in Domain Access Control Register

b00

No access

Any access generates a domain fault

b01

Client Accesses 

are 

checked against the access 

permission bits in the section or page descriptor

b10

Reserved

Reserved. Currently behaves like the no access 
mode

b11

Manager

Accesses are not checked against the access 
permission bits so a permission fault cannot be 
generated

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15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0