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

Table Of Contents
B-46 Vol. 3
MODEL-SPECIFIC REGISTERS (MSRS)
37 Unique DCU Prefetcher Disable. (R/W)
When set to 1, The DCU L1 data cache
prefetcher is disabled. The default value after
reset is 0. BIOS may write ‘1’ to disable this
feature.
The DCU prefetcher is an L1 data cache
prefetcher. When the DCU prefetcher detects
multiple loads from the same line done within
a time limit, the DCU prefetcher assumes the
next line will be required. The next line is
prefetched in to the L1 data cache from
memory or L2.
38 Shared IDA Disable. (R/W)
When set to 1 on processors that support IDA,
the Intel Dynamic Acceleration feature (IDA) is
disabled and the IDA_Enable feature flag will
be clear (CPUID.06H: EAX[1]=0).
When set to a 0 on processors that support
IDA, CPUID.06H: EAX[1] reports the
processor’s support of IDA is enabled.
Note: the power-on default value is used by
BIOS to detect hardware support of IDA. If
power-on default value is 1, IDA is available in
the processor. If power-on default value is 0,
IDA is not available.
39 Unique IP Prefetcher Disable. (R/W)
When set to 1, The IP prefetcher is disabled.
The default value after reset is 0. BIOS may
write ‘1’ to disable this feature.
The IP prefetcher is an L1 data cache
prefetcher. The IP prefetcher looks for
sequential load history to determine whether
to prefetch the next expected data into the
L1 cache from memory or L2.
63:40 Reserved.
Table B-3. MSRs in Processors Based on Intel Core Microarchitecture (Contd.)
Register
Address Register Name
Shared/
Unique Bit Description
Hex Dec