82830MP Datasheet, PDF(102/159 Page) Intel Corporation – Intel 830MP Chipset: 82830MP Graphics and Memory Controller Hub (GMCH-M)

English

English German Russian Spanish Italian Polish Chinese Japanese Korean French Portuguese	Language :

82830MP Datasheet, PDF (102/159 Pages) Intel Corporation – Intel 830MP Chipset: 82830MP Graphics and Memory Controller Hub (GMCH-M)

◁

IntelÂ® 830MP Chipset

Table 24. Memory Segments and Attributes

Memory Segments

Attributes

000000H - 09FFFFH

0A0000H - 0BFFFFH

0C0000H - 0C3FFFH

0C4000H - 0C7FFFH

0C8000H - 0CBFFFH

0CC000H - 0CFFFFH

0D0000H - 0D3FFFH

0D4000H - 0D7FFFH

0D8000H - 0DBFFFH

0DC000H - 0DFFFFH

0E0000H - 0E3FFFH

0E4000H - 0E7FFFH

0E8000H - 0EBFFFH

0EC000H - 0EFFFFH

0F0000H - 0FFFFFH

Fixed - always mapped to main SDRAM

Mapped to hub interface, or AGP -

configurable as SMM space

WE RE

Comments

0 to 640K â DOS Region

Video Buffer (physical SDRAM

configurable as SMM space)

Add-on BIOS

BIOS Extension

BIOS Area

5.1.2.1

5.1.2.2

5.1.2.3

5.1.2.4

DOS Area (00000h-9FFFFh)

The DOS area is 640 KB in size and is always mapped to the main memory controlled by the GMCH-M.

Legacy VGA Ranges (A0000h-BFFFFh)

The legacy 128-KB VGA memory range A0000h-BFFFFh (Frame Buffer) can be mapped to AGP/PCI1

(Device #1) and/or to the hub interface depending on the programming of the VGA steering bits.

Priority for VGA mapping is constant in that the GMCH-M always decodes internally mapped devices

first. The GMCH-M always positively decodes internally mapped device, namely AGP/PCI1.

Subsequent decoding of regions mapped to AGP/PCI1or the hub interface depends on the Legacy VGA

configurations bits (VGA Enable and MDAP). This region is also the default for SMM space.

Compatible SMRAM Address Range (A0000h-BFFFFh)

When compatible SMM space is enabled, SMM-mode CPU accesses to this range are routed to physical

system SDRAM at this address. Non-SMM-mode CPU accesses to this range are considered to be to the

Video Buffer Area as described above. AGP and hub interface originated cycles to enabled SMM space

are not allowed and are considered to be to the Video Buffer Area.

Monochrome Adapter (MDA) Range (B0000h - B7FFFh)

Legacy support requires the ability to have a second graphics controller (monochrome) in the system.

Accesses in the VGA range are forwarded to AGP/PCI1 and the hub interface (depending on

102

Datasheet

298338-001

▷