s3c2410a Samsung Semiconductor, Inc., s3c2410a Datasheet - Page 560

• Manufacturer Part Number: s3c2410a
• Description: 16/32-bit Risc Arm Microprocessor
• Manufacturer: Samsung Semiconductor, Inc.

MMU
LEVEL ONE DESCRIPTOR
The level one descriptor returned is either a section descriptor a coarse page table descriptor, or a fine page table
descriptor. A section descriptor provides the base address of a 1MB block of memory. The page table descriptors
provide the base address of a page table that contains level two descriptors.
There are two sizes of page table:
The two least significant bits indicate the descriptor type
3-8
31
coarse page tables have 256 entries, splitting the 1MB the table describes into 4KB blocks
fine page tables have 1024 entries, splitting the 1MB the table describes into 1KB blocks
Value
Section base address
00
01
10
11
Fine page table base address
Coarse page table base address
Invalid
Coarse page table
Section
Fine page table
Meaning
Table 3-2. Interpreting Level One Descriptor Bits [1:0]
20
19
Figure 3-4. Level One Descriptors
Generates a section translation fault.
Indicates that this is a coarse page table descriptor.
Indicates that this is a section descriptor.
Indicates that this is a fine page table descriptor.
12
11
AP
10 9
8
Domain
Domain
Domain
Notes
5
4 3
1
1
1
C B
2
1
0
0
1
1
ARM920T PROCESSOR
0
0
1
0
1
Fault
Coarse page table
Section
Fine page table