
W O R K I N G W I T H T H E C P U
MemoryManagement Unit (MMU)
118
Hardware Reference NS9215
Translation
sequence for tiny
page references
Page translation involves one additional step beyond that of a section translation.
The first-level descriptor is the fine page table descriptor; this points to the first-
level descriptor.
Note:
The domain specified in the first-level description and access permissions
specified in the first-level description together determine whether the access
has permissions to proceed. See “Domain access control” on page 121 for
more information.
Subpages
You can define access permissions for subpages of small and large pages. If, during a
page table walk, a small or large page has a different subpage permission, only the
subpage being accessed is written into the TLB. For example, a 16 KB (large page)
subpage entry is written into the TLB if the subpage permission differs, and a 64 KB
entry is put in the TLB if the subpage permissions are identical.
31
14 13
0
Translation base
1
Translation table base
31
14 13
0
Translation base
2
Table index
0 0
31
20 19
0
Table index
Page index
First-level descriptor
31
0
Fine page table base address
2
1 1
1
3
4
5
Domain 1
31
0
Fine page table base address
Level two
table index
10 9
Modified virtual address
8
11
12
1
2
11
12
31
10 9
6 5 4 3 2 1 0
0
0
L2 table index
1
1
B
C
AP
Page base address
Page base address
31
0
10 9
Page index
Physical address
Second-level descriptor
Содержание NS9215
Страница 1: ...NS9215 Hardware Reference 90000847_C Release date 10 April 2008...
Страница 3: ......
Страница 4: ......
Страница 26: ...26 Hardware Reference NS9215...
Страница 44: ...P I N O U T 26 5 System clock 44 Hardware Reference NS9215 System clock drawing...
Страница 52: ...P I N O U T 26 5 Power and ground 52 Hardware Reference NS9215...
Страница 80: ...I O C O N T ROL M O D U L E Memory Bus Configuration register 80 Hardware Reference NS9215...
Страница 136: ...WOR KI N G W I TH T H E C P U Noncachable instruction fetches 136 Hardware Reference NS9215...
Страница 202: ...S Y S T E M C O N T RO L M OD U L E RTC Module Control register 202 Hardware Reference NS9215...
Страница 260: ...M E MO R Y C O N T ROL L E R StaticMemory Turn Round Delay 0 3 registers 260 Hardware Reference NS9215...
Страница 354: ...E X T E R N A L D M A DMA Peripheral Chip Select register 354 Hardware Reference NS9215...
Страница 362: ...A E S D AT A E N C R Y P T I O N D E C R Y P T I O N M O D U L E CCM mode 362 Hardware Reference NS9215...
Страница 384: ...I O HU B M OD UL E Module Direct Mode TX Data Last FIFO 384 Hardware Reference NS9215 31 March 2008...
Страница 414: ...S E R I A L C ON T RO L M O D U L E U ART UART Modem Status register 414 Hardware Reference NS9215...
Страница 446: ...S E R I A L C ON T RO L M O D U L E S PI SPI timing characteristics 446 Hardware Reference NS9215...
Страница 472: ...R E A L TI M E C L O C K M O D U L E General Status register 472 Hardware Reference NS9215...
Страница 512: ...TI M I NG Clock timing 512 Hardware Reference NS9215...
Страница 514: ...PA CKA GING Processor Dimensions 514 Hardware Reference NS9215 P r o c e s s o r D i m e n s i o n s...
Страница 515: ...PA CKA GING Processor Dimensions www digiembedded com 515...
Страница 516: ...PA CKA GING Processor Dimensions 516 Hardware Reference NS9215...