Intel IA-32 - Manual (Page 452)

10-12 Vol. 3A
MEMORY CACHE CONTROL
Figure 10-2. Cache-Control Registers and Bits Available in IA-32 Processors
Page-Directory or
Page-Table Entry
TLBs
MTRRs
3
Physical Memory
0
FFFFFFFFH 2
control overall caching
of system memory
CD and NW Flags PCD and PWT flags
control page-level
caching
G flag controls page-
level flushing of TLBs
MTRRs control caching
of selected regions of
physical memory
P
C
D
CR3
Control caching of
page directory
P
W
T
C
D
CR0
N
W
Store Buffer
P
C
D
P
W
T
G 1
CR4
Enables global pages
P
G
E
designated with G flag
1. G flag only available in Pentium 4, Intel Xeon, and P6 family
3. MTRRs available only in Pentium 4 and P6 family processors;
similar control available in Pentium processor with the KEN#
and WB/WT# pins.
2. The maximum physical address size is reported by CPUID leaf
function 80000008H. The maximum physical address size of
PAT 4
PAT controls caching
of virtual memory
pages
4. PAT available only in Pentium III and Pentium 4 processors.
P 4
A
T
processors.
IA32_MISC_ENABLE MSR
3 rd Level
Cache Disable
FFFFFFFFFH applies only If 36-bit physical addressing is used.