Translation For A Large Page; First−Level Descriptor Contents - Texas Instruments OMAP5910 Reference Manual

Table 20. First−Level Descriptor Contents
Least-Significant
Two Bits of Des-
criptor Contents
00b Any access to the page in virtual memory corresponding to this descriptor will generate
a fault. As described in section 6.2.7, the fault error must be addressed by the MPU
core. Until the error is cleared, the DSP EMIF will be stalled, therefore stalling the
original requestor (either the DSP core or DMA).
01b The descriptor contains the base address for a large page. Section 6.2.6.2 describes
the translation process for a large page.
10b The descriptor contains the base address for a small page. Section 6.2.6.3 describes
the translation process for a small page.
11b The descriptor provides the base address of a tiny page (fine page tables only).
Section 6.2.6.3 describes the translation process for a tiny page.
6.2.6.2 Translating Large Pages
Figure 41.

Translation for a Large Page

31
Large page base address
31
Large page base address
Legend: AP = Access Permissions: 00 or 01 = no access, 10 = read only, 11 = full access; X = don't care
SPRU890A
Figure 41 describes how the contents of a large page descriptor are used to
calculate the physical address of the DSP virtual address.
23
X
Descriptor Contents Meaning
Second-level descriptor contents
16 15
X
16 15
16 15
DSP Memory Management Unit
6 5 4 3 2
AP X
DSP virtual address
Page index
Physical address
Page index
DSP Subsystem
0
1
0 1
0
0
89