HP A2Y15AV Manual Do Utilizador
Datasheet, Volume 2
69
Processor Configuration Registers
2.5.25
PAM4—Programmable Attribute Map 4 Register
This register controls the read, write and shadowing attributes of the BIOS range from
D8000h to DFFFFh. The Uncore allows programmable memory attributes on 13 legacy
memory segments of various sizes in the 768 KB to 1 MB address range. Seven
Programmable Attribute Map (PAM) registers are used to support these features.
Cacheability of these areas is controlled using the MTRR register in the core.
D8000h to DFFFFh. The Uncore allows programmable memory attributes on 13 legacy
memory segments of various sizes in the 768 KB to 1 MB address range. Seven
Programmable Attribute Map (PAM) registers are used to support these features.
Cacheability of these areas is controlled using the MTRR register in the core.
Two bits are used to specify memory attributes for each memory segment. These bits
apply to host accesses to the PAM areas. These attributes are:
apply to host accesses to the PAM areas. These attributes are:
• RE – Read Enable. When RE=1, the host read accesses to the corresponding
memory segment are claimed by the Uncore and directed to main memory.
Conversely, when RE=0, the host read accesses are directed to DMI.
Conversely, when RE=0, the host read accesses are directed to DMI.
• WE – Write Enable. When WE=1, the host write accesses to the corresponding
memory segment are claimed by the Uncore and directed to main memory.
Conversely, when WE=0, the host read accesses are directed to DMI.
Conversely, when WE=0, the host read accesses are directed to DMI.
The RE and WE attributes permit a memory segment to be Read Only, Write Only,
Read/Write or Disabled. For example, if a memory segment has RE=1 and WE=0, the
segment is Read Only.
Read/Write or Disabled. For example, if a memory segment has RE=1 and WE=0, the
segment is Read Only.
B/D/F/Type:
0/0/0/PCI
Address Offset:
84h
Reset Value:
00h
Access:
RW
Size:
8 bits
BIOS Optimal Default
0h
Bit
Access
Reset
Value
RST/
PWR
Description
7:6
RO
0h
Reserved (RSVD)
5:4
RW
00b
Uncore
0DC000–0DFFFF Attribute (HIENABLE)
This field controls the steering of read and write cycles that
This field controls the steering of read and write cycles that
address the BIOS area from 0DC000h to 0DFFFFh.
00 = DRAM Disabled. All accesses are directed to DMI.
01 = Read Only. All reads are sent to DRAM, all writes are
00 = DRAM Disabled. All accesses are directed to DMI.
01 = Read Only. All reads are sent to DRAM, all writes are
forwarded to DMI.
10 = Write Only. All writes are sent to DRAM, all reads are
serviced by DMI.
11 = Normal DRAM Operation. All reads and writes are serviced
by DRAM.
This register is locked by Intel TXT.
3:2
RO
0h
Reserved (RSVD)
1:0
RW
00b
Uncore
0D8000–0DBFFF Attribute (LOENABLE)
This field controls the steering of read and write cycles that
This field controls the steering of read and write cycles that
address the BIOS area from 0D8000h to 0DBFFFh.
00 = DRAM Disabled. All reads are sent to DRAM. All writes are
00 = DRAM Disabled. All reads are sent to DRAM. All writes are
forwarded to DMI.
01 = Read Only. All reads are sent to DRAM. All writes are
forwarded to DMI.
10 = Write Only. All writes are sent to DRAM. All reads are
serviced by DMI.
11 = Normal DRAM Operation. All reads and writes are serviced
by DRAM.
This register is locked by Intel TXT.