
W O R K I N G W I T H T H E C P U
MemoryManagement Unit (MMU)
112
Hardware Reference NS9215
Section descriptor
bit description
Coarse page table
descriptor
A coarse page table descriptor provides the base address of a page table that
contains second-level descriptors for either large page or small page accesses.
Coarse page tables have 256 entries, splitting the 1 MB that the table describes into
4 KB blocks.
Note:
If a coarse page table descriptor is returned from the first-level fetch, a
second-level fetch is initiated.
Coarse page table
descriptor format
Coarse page table
descriptor bit
description
Fine page table
descriptor
A fine page table descriptor provides the base address of a page table that contains
second-level descriptors for large page, small page, or tiny page accesses. Fine
Bits
Description
[31:20]
Forms the corresponding bits of the physical address for a section.
[19:12]
Always written as 0.
[11:10]
Specify the access permissions for this section.
[09]
Always written as 0.
[8:5]
Specifies one of the 16 possible domains (held in the Domain and Access Control
register) that contain the primary access controls.
4
Should be written as 1, for backwards compatibility.
[3:2]
Indicate if the area of memory mapped by this section is treated as writeback cachable,
write-through cachable, noncached buffered, or noncached nonbuffered.
[1:0]
Must be
10
to indicate a section descriptor.
Coarse page table base address
S
B
Z
1
0
1
1
0
2
3
4
5
8
9
31
SBZ
10
Domain
Bits
Description
[31:10]
Forms the base for referencing the second-level descriptor (the coarse page table index
for the entry derived from the MVA).
9
Always written as 0.
[8:5]
Specifies one of the 16 possible domains (held in the Domain Access Control registers)
that contain the primary access controls.
4
Always written as 1.
[3:2]
Always written as 0.
[1:0]
Must be
01
to indicate a coarse page descriptor.
Содержание NS9215
Страница 1: ...NS9215 Hardware Reference 90000847_C Release date 10 April 2008...
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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...