Processor Configuration Registers
134
Datasheet, Volume 2
2.8.10
GTTMMADR—Graphics Translation Table, Memory Mapped
Range Address Register
This register requests allocation for the combined Graphics Translation Table
Modification Range and Memory Mapped Range. The range requires 4 MB combined for
MMIO and Global GTT aperture, with 2MB of that used by MMIO and 2 MB used by GTT.
GTTADR will begin at (GT 2 MB) while the MMIO base address will be the
same as GTTMMADR.
For the Global GTT, this range is defined as a memory BAR in graphics device
configuration space. It is an alias into which software is required to write Page Table
Entry values (PTEs). Software may read PTE values from the global Graphics
Translation Table (GTT). PTEs cannot be written directly into the global GTT memory
area.
The device snoops writes to this region in order to invalidate any cached translations
within the various TLBs implemented on-chip.
The allocation is for 4 MB and the base address is defined by bits 38:22.
B/D/F/Type:
0/2/0/PCI
Address Offset:
10–17h
Reset Value:
0000000000000004h
Access:
RW, RO
Size:
64 bits
Bit
Attr
Reset
Value
RST/
PWR
Description
63:39
RW
0000000h
FLR,
Uncore
Reserved for Memory Base Address (RSVDRW)
Must be set to 0 since addressing above 512 GB is not supported.
38:22
RW
00000h
FLR,
Uncore
Memory Base Address (MBA)
Set by the OS, these bits correspond to address signals [38:22].
4 MB combined for MMIO and Global GTT table aperture (2 MB for
MMIO and 2 MB for GTT).
21:4
RO
00000h
Uncore
Address Mask (ADM)
Hardwired to 0s to indicate at least 4 MB address range.
3
RO
0b
Uncore
Prefetchable Memory (PREFMEM)
Hardwired to 0 to prevent prefetching.
2:1
RO
10b
Uncore
Memory Type (MEMTYP)
00 = To indicate 32 bit base address
01 = Reserved
10 = To indicate 64 bit base address
11 = Reserved
0
RO
0b
Uncore
Memory/IO Space (MIOS)
Hardwired to 0 to indicate memory space.
Содержание 2ND GENERATION CORE PROCESSOR FAMILY DESKTOP - VOLUME 2 01-2011
Страница 12: ...Introduction 12 Datasheet Volume 2...