HP A2Y15AV Manuale Utente

Datasheet, Volume 2

65

Processor Configuration Registers 

This register controls the read, write and shadowing attributes of the BIOS range from 
F_0000h to F_FFFFh. 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:

• 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.

• 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.

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. 

7:6

RO

0h

5:4

RW

00b

Uncore

0F0000–0FFFFF Attribute (HIENABLE) 
This field controls the steering of read and write cycles that 

address the BIOS area from 0F_0000h to 0F_FFFFh.
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.

3:0

RO

0h