AC82G41SLGQ3 Datasheet, PDF (117/604 Pages) Intel Corporation – Intel® 4 Series Chipset Family

DRAM Controller Registers (D0:F0)
5.1.34
TSEGMB—TSEG Memory Base
B/D/F/Type:
Address Offset:
Default Value:
Access:
Size:
0/0/0/PCI
AC-AFh
00000000h
RO, R/W/L
32 bits
This register contains the base address of TSEG DRAM memory. BIOS determines the base of
TSEG memory by subtracting the TSEG size (PCI Device 0, offset 9Eh, bits 2:1) from graphics GTT
stolen base (PCI Device 0, offset A8h, bits 31:20).
Once D_LCK has been set, these bits becomes read only.
Bit
31:20
19:0
5.1.35
Access
Default
Value
RST/PWR
Description
R/W/L
000h
RO
00000h
Core
Core
TESG Memory base (TSEGMB): This register contains
bits 31:20 of the base address of TSEG DRAM memory.
BIOS determines the base of TSEG memory by subtracting
the TSEG size (PCI Device 0, offset 9Eh, bits 2:1) from
graphics GTT stolen base (PCI Device 0, offset A8h, bits
31:20).
Once D_LCK has been set, these bits becomes read only.
Reserved
TOLUD—Top of Low Usable DRAM
B/D/F/Type:
Address Offset:
Default Value:
Access:
Size:
0/0/0/PCI
B0-B1h
0010h
R/W/L, RO
16 bits
This 16 bit register defines the Top of Low Usable DRAM. TSEG, GTT Graphics memory
and Graphics Stolen Memory are within the DRAM space defined. From the top, (G)MCH
optionally claims 1 to 64 MB of DRAM for internal graphics if enabled, 1, 2 MB of DRAM
for GTT Graphics Stolen Memory (if enabled) and 1, 2, or 8 MB of DRAM for TSEG if
enabled.
Programming Example:
C1DRB3 is set to 4 GB
TSEG is enabled and TSEG size is set to 1 MB
Internal Graphics is enabled, and Graphics Mode Select is set to 32 MB
GTT Graphics Stolen Memory Size set to 2 MB
BIOS knows the operating system requires 1 GB of PCI space.
BIOS also knows the range from FEC0_0000h to FFFF_FFFFh is not usable by the
system. This 20 MB range at the very top of addressable memory space is lost to APIC
and Intel TXT (82Q45/82Q43 GMCH only).
According to the above equation, TOLUD is originally calculated to:
4 GB = 1_0000_0000h
The system memory requirements are: 4 GB (max addressable space) – 1 GB (PCI
space) – 35 MB (lost memory) = 3 GB – 35 MB (minimum granularity) = ECB0_0000h.
Datasheet
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