Page Table Format; Coarse - Texas Instruments OMAP5912 Reference Manual

DSP Memory Management Unit
7.2.2

Page Table Format

Figure 14. Level One Descriptor
31:20
Coarse page table base address
Section base address
Fine page table base address
Note: AP = Protection bits for the page.
Note: R indicates reserved bits to be written as 0 and read value to be ignored.
Figure 15. Level Two Descriptor
31:16
Large page table base address
Small page table base address
Tiny page table base address
Note: AP = Protection bits for the page.
Note: R indicates reserved bits to be written as 0 and read value to be ignored.
Table 18. Page Protection Field
7.2.3 Coarse Page Tables
64 DSP Subsystem
19:12
15:12
R
AP Access
0x No access
10 Read only
11 Full access
Coarse page tables have 256 entries and each entry describes 4K bytes.
These entries provide a base address for either small or large pages. Large
page descriptors must be repeated in 16 consecutive entries.
11:10 9:2 1 0
0 0 Fault
R 0 1 Coarse page
AP 1 0 Section
R 1 1 Fine page
11:10 9:6 5:4 3:2
AP R
R AP R
R AP R
Description
Any access causes a permission fault.
Write causes a permission fault.
Read and write access allowed.
1 0
0 0 Fault
0 1 Large page
1 0 Small page
1 1 Tiny page
SPRU750A