Intel 64 and IA-32 Architectures Software Developers Manual Volume 3B, System Programming Guide Part 2

Table Of Contents
B-16 Vol. 3
MODEL-SPECIFIC REGISTERS (MSRS)
23 xTPR Message Disable.
(R/W)
When set to 1, xTPR
messages are disabled. xTPR
messages are optional
messages that allow the
processor to inform the
chipset of its priority.
if
CPUID.01H:ECX[1
4] = 1
33:24 Reserved
34 XD Bit Disable. (R/W)
When set to 1, the Execute
Disable Bit feature (XD Bit) is
disabled and the XD Bit
extended feature flag will be
clear (CPUID.80000001H:
EDX[20]=0).
if
CPUID.80000001
H:EDX[20] = 1
When set to a 0 (default),
the Execute Disable Bit
feature (if available) allows
the OS to enable PAE paging
and take advantage of data
only pages.
BIOS must not alter the
contents of this bit location,
if XD bit is not supported..
Writing this bit to 1 when
the XD Bit extended feature
flag is set to 0 may generate
a #GP exception.
63:35 Reserved
1A2H 418 IA32_TEMPERATURE_TAR
GET
Processor Temperature. (R)
Software visible processor T
j
parameter.
15:0 Reserved.
Table B-2. IA-32 Architectural MSRs (Contd.)
Register Address Architectural MSR Name
and bit fields
(Former MSR Name) MSR/Bit Description
Introduced as
Architectural
MSR
Hex Decimal