
. . . . .
W O R K I N G W I T H T H E C P U
MemoryManagement Unit (MMU)
www.digiembedded.com
111
First-level
descriptor bit
assignments:
Priority encoding
of fault status
First-level
descriptor bit
assignments:
Interpreting first
level descriptor
bits [1:0]
Section descriptor
A section descriptor provides the base address of a 1 MB block of memory.
Section descriptor
format
Bits
Section
Coarse
Fine
Description
[31:20]
[31:10]
[31:12]
Forms the corresponding bits of the physical address.
[19:12]
----
---
SHOULD BE ZERO
[11:10]
---
---
Access permission bits. See “Access permissions and
domains” on page 106 and “Fault Address and Fault Status
registers” on page 119 for information about interpreting
the access permission bits.
9
9
[11:9]
SHOULD BE ZERO
[8:5]
[8:5]
[8:5]
Domain control bits
4
4
4
Must be 1.
[3:2]
---
---
Bits C and B indicate whether the area of memory mapped
by this page is treated as write-back cachable, write-
through cachable, noncached buffered, or noncached
nonbuffered.
---
[3:2]
[3:2]
SHOULD BE ZERO
[1:0]
[1:0]
[1:0]
These bits indicate the page size and validity, and are
interpreted as shown in “First-level descriptor bit
assignments: Priority encoding of fault status” on
page 111.
Value
Meaning
Description
0 0
Invalid
Generates a section translation fault.
0 1
Coarse page table
Indicates that this is a coarse page table descriptor.
1 0
Section
Indicates that this is a section descriptor.
1 1
Fine page table
Indicates that this is a fine page table descriptor.
Section base address
SBZ
S
B
Z
AP
Domain
1
1
0
C
B
1
0
2
3
4
5
8
9
10
11
12
19
20
31
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...