MPU Memory Management Unit
2-33
MPU Subsystem
Table 2–19. Level 1 Coarse Page Table Descriptor
Bit
Name
Function
31–10
COARSE_PG_BASE
Base address used to access the coarse page table entry. The coarse
page table index selecting an entry is derived from the virtual address. If a
page table descriptor is returned from the level 1 fetch (Bit 0 = 1), a level
2 fetch is initiated.
9
RESERVED
Reserved. Must always be written to as 0.
8–5
DOMAIN
Specify which one of the 16 domains (held in the domain access control
register) contains the primary access controls.
4
RESERVED
Reserved. Must be written to as 1 for backward compatibility.
3–2
RESERVED
Reserved. Must be written as 0.
1–0
RESERVED
Reserved. Must be written as 1.
Table 2–20. Level 1 Section Descriptor
Bit
Name
Function
31–20
SECTION_BASE
The 12 MSBs of the address of the section in physical memory (section
base address).
19–12
Reserved
Must always be written to as 0.
11–10
AP
Specify the access permissions for this section (see Table 2–24).
9
Reserved
Must always be written to as 0.
8–5
DOMAIN
Specify which one of the 16 domains (held in the domain access control
register) contains the primary access controls.
4
Reserved
Must be written to as 1 for backward compatibility.
3
C
Cacheable (C_MMU): indicates that data or instructions at this address
are placed in the cache if the cache is enabled.
2
B
Bufferable (B_MMU): indicates that data writes at this address are
buffered if the write buffer is enabled.