Intel IA-32 - Manual (Page 469)

Vol. 3A 10-29
MEMORY CACHE CONTROL
For the P6 family processors, the prefix for the fixed range MTRRs is MTRRfix.
10.11.2.3 Variable Range MTRRs
The Pentium 4, Intel Xeon, and P6 family processors permit software to specify the memory
type for eight variable-size address ranges, using a pair of MTRRs for each range. The first entry
in each pair (IA32_MTRR_PHYSBASEn) defines the base address and memory type for the
range; the second entry (IA32_MTRR_PHYSMASKn) contains a mask used to determine the
address range. The “n” suffix indicates register pairs 0 through 7.
For P6 family processors, the prefixes for these variable range MTRRs are MTRRphysBase and
MTRRphysMask.
Figure 10-6 shows flags and fields in these registers. The functions of these flags and fields are:
•
Type field, bits 0 through 7 — Specifies the memory type for the range (see Table 10-8
for the encoding of this field).
Table 10-9. Address Mapping for Fixed-Range MTRRs
Address Range (hexadecimal) MTRR
63 56 55 48 47 40 39 32 31 24 23 16 15 8 7 0
70000-
7FFFF 60000-
6FFFF 50000-
5FFFF 40000-
4FFFF 30000-
3FFFF 20000-
2FFFF 10000-
1FFFF 00000-
0FFFF IA32_MTRR_
FIX64K_00000
9C000
9FFFF 98000-
98FFF 94000-
97FFF 90000-
93FFF 8C000-
8FFFF 88000-
8BFFF 84000-
87FFF 80000-
83FFF IA32_MTRR_
FIX16K_80000
BC000
BFFFF B8000-
BBFFF B4000-
B7FFF B0000-
B3FFF AC000-
AFFFF A8000-
ABFFF A4000-
A7FFF A0000-
A3FFF IA32_MTRR_
FIX16K_A0000
C7000
C7FFF C6000-
C6FFF C5000-
C5FFF C4000-
C4FFF C3000-
C3FFF C2000-
C2FFF C1000-
C1FFF C0000-
C0FFF IA32_MTRR_
FIX4K_C0000
CF000
CFFFF CE000-
CEFFF CD000-
CDFFF CC000-
CCFFF CB000-
CBFFF CA000-
CAFFF C9000-
C9FFF C8000-
C8FFF IA32_MTRR_
FIX4K_C8000
D7000
D7FFF D6000-
D6FFF D5000-
D5FFF D4000-
D4FFF D3000-
D3FFF D2000-
D2FFF D1000-
D1FFF D0000-
D0FFF IA32_MTRR_
FIX4K_D0000
DF000
DFFFF DE000-
DEFFF DD000-
DDFFF DC000-
DCFFF DB000-
DBFFF DA000-
DAFFF D9000-
D9FFF D8000-
D8FFF IA32_MTRR_
FIX4K_D8000
E7000
E7FFF E6000-
E6FFF E5000-
E5FFF E4000-
E4FFF E3000-
E3FFF E2000-
E2FFF E1000-
E1FFF E0000-
E0FFF IA32_MTRR_
FIX4K_E0000
EF000
EFFFF EE000-
EEFFF ED000-
EDFFF EC000-
ECFFF EB000-
EBFFF EA000-
EAFFF E9000-
E9FFF E8000-
E8FFF IA32_MTRR_
FIX4K_E8000
F7000
F7FFF F6000-
F6FFF F5000-
F5FFF F4000-
F4FFF F3000-
F3FFF F2000-
F2FFF F1000-
F1FFF F0000-
F0FFF IA32_MTRR_
FIX4K_F0000
FF000
FFFFF FE000-
FEFFF FD000-
FDFFF FC000-
FCFFF FB000-
FBFFF FA000-
FAFFF F9000-
F9FFF F8000-
F8FFF IA32_MTRR_
FIX4K_F8000