2-10
The SPARC CPU
Cache Controller and Memory Management Unit
PTP
This bit, when set, indicates that a page table pointer is
contained in this entry
Page Table Field
This field can contain a PTE, PTP or I/O PTE. It can be read
and written using ASI 0x06 (25 bits).
Page Table Entry
The PTE defines the physical address of a page and its access permission.
It contains the following information:
Bits 31:27
Reserved - always write 0.
Bits 26:8
PPN – Physical Page Number, which provides the upper 19
bits (30:12) of the 31-bit physical address of the page.
Bit 7
Cacheable. This bit when set indicates that a page is
cacheable.
Bit 6
Modified. This bit is set when the page is written to.
Bit 5
Always 1 for a PTE in the TLB. For a PTE in physical
memory, this bit is set when the page is accessed.
Bits 4:2
ACC – Access Permissions. This field indicates whether
access is permitted for the transaction being attempted. The
Address Space Identifier (ASI) determines whether the an
access is an instruction or data access, and whether it is a
user or supervisor access.
Bits 1:0
ET – These are set to 10 indicate an entry type of PTE.
00 = Invalid
01 = Page Table Pointer
10 = Page Table Entry
11 = Reserved in Page Tables
ACC
User
Supervisor
000
Read Only
Read Only
001
Read/Write
Read/Write
010
Read/Execute
Read/Execute
011
Read/Write/Execute
Read/Write/Execute
100
Execute Only
Execute Only
101
Read Only
Execute Only
110
No Access
Read/Execute
111
No Access
Read/Write/Execute
Table 2-3 Page Table Access Permissions
S3GX_TRMBook Page 10 Friday, September 19, 1997 11:39 am
Содержание SPARCbook 3 series
Страница 1: ...Series Technical Reference Manual 980327 02 3 S3GX_TRMBook Page i Friday September 19 1997 11 39 am...
Страница 8: ...viii S3GX_TRMBook Page viii Friday September 19 1997 11 39 am...
Страница 28: ...1 16 Architecture Overview Microcontroller Subsystem S3GX_TRMBook Page 16 Friday September 19 1997 11 39 am...
Страница 44: ...2 16 The SPARC CPU SBus Controller S3GX_TRMBook Page 16 Friday September 19 1997 11 39 am...
Страница 76: ...5 8 SCSI Controller DMA Support S3GX_TRMBook Page 8 Friday September 19 1997 11 39 am...
Страница 82: ...6 6 Ethernet Interface DMA Support for Network Operations S3GX_TRMBook Page 6 Friday September 19 1997 11 39 am...
Страница 96: ...7 14 PCMCIA Interface Microcontroller Registers S3GX_TRMBook Page 14 Friday September 19 1997 11 39 am...
Страница 146: ...9 28 MODEM Class 2 Fax Command Set S3GX_TRMBook Page 28 Friday September 19 1997 11 39 am...
Страница 180: ...11 30 Display Interface RAMDAC S3GX_TRMBook Page 30 Friday September 19 1997 11 39 am...
Страница 210: ...B 10 Connector Information Removable Hard Drive SCSI Connector S3GX_TRMBook Page 10 Friday September 19 1997 11 39 am...
Страница 216: ...Index vi S3GX_TRMBook Page vi Friday September 19 1997 11 39 am...