Extended System Bios Area E0000h-EFFFFh | Intel D15343-003 guide

Intel® 82854 Graphics Memory Controller Hub (GMCH)

Extended System BIOS Area (E0000h-EFFFFh)

This 64-kB area is divided into four 16-kB segments that can be assigned with different attributes via PAM Control register as defined in Figure 4 and Table 21.

System BIOS Area (F0000h-FFFFFh)

This area is a single 64-kB segment that can be assigned with different attributes via PAM Control register as defined in Figure 4 and Table 21.

4.8.18SMRAM – System Management RAM Control Register (Device #0)

Address Offset:	60h
Default Value:	02h
Access:	Read/Write/Lock, Read Only
Size:	8 bits

The SMRAM register controls how accesses to Compatible and Extended SMRAM spaces are treated. The Open, Close, and Lock Bits function only when G_SMRAME Bit is set to a 1. Also, the Open Bit must be Reset before the LOCK Bit is set.

Bit	Description

7	Reserved

6	SMM Space Open (D_OPEN): When D_OPEN=1 and D_LCK=0, the SMM space DDR
	SDRAM is made visible even when SMM decode is not active. This is intended to help BIOS
	initialize SMM space. Software should ensure that D_OPEN=1 and D_CLS=1 are not set at the
	same time. When D_LCK is set to a 1, D_OPEN is Reset to 0 and becomes Read Only.

5	SMM Space Closed (D_CLS): When D_CLS = 1 SMM Space, DDR SDRAM is not accessible
	to data references, even if SMM decode is active. Code references may still access SMM
	space DDR SDRAM. This will allow SMM software to reference “through” SMM space to
	update the display even when SMM is mapped over the VGA range. Software should ensure
	that D_OPEN=1 and D_CLS=1 are not set at the same time. D_CLS applies to all SMM spaces
	(Cseg, Hseg, and Tseg).

4	SMM Space Locked (D_LCK): When D_LCK is set to 1, then D_OPEN is Reset to 0 and
	D_LCK, D_OPEN, G_SMRAME, C_BASE_SEG, GMS, DRB, DRA, H_SMRAM_EN, TSEG_SZ
	and TSEG_EN become Read Only. D_LCK can be set to 1 via a normal Configuration Space
	Write but can only be cleared by a Full Reset. The combination of D_LCK and D_OPEN
	provide convenience with security. The BIOS can use the D_OPEN function to initialize SMM
	space and then use D_LCK to “lock down” SMM space in the future so that no application
	software (or BIOS itself) can violate the integrity of SMM space, even if the program has
	knowledge of the D_OPEN function.

3	Global SMRAM Enable (G_SMRAME): If set to a 1, then Compatible SMRAM functions is
	enabled, providing 128 kB of DDR SDRAM accessible at the A0000h address while in SMM
	(ADS# with SMM decode). To enable Extended SMRAM function this bit must be set to 1, refer
	to the section on SMM for more details. Once D_LCK is set, this bit becomes Read Only.

2:0	Compatible SMM Space Base Segment (C_BASE_SEG)—RO: This field indicates the
	location of SMM space. “SMM DRAM” is not remapped. It is simply “made visible” if the
	conditions are right to access SMM space, otherwise the access is forwarded to Hub interface.
	C_BASE_SEG is hardwired to 010 to indicate that the GMCH supports the SMM space at
	A0000h–BFFFFh.

64	D15343-003

Image 64

Intel D15343-003 manual Smram System Management RAM Control Register Device #0, Extended System Bios Area E0000h-EFFFFh

Contents

Datasheet Intel 82854 Graphics Memory Controller Hub Gmch D15343-003 Contents Intel 82854 Graphics Memory Controller Hub Gmch 10.9 127 Figures 152 Revision History Date Revision Description Intel 82854 Graphics Memory Controller Hub Gmch Processor/Host Bus Support OverviewMemory System Video Stream Decoder System InterruptsVideo Overlay Internal Graphics Features Display Intel 82854 Graphics Memory Controller Hub Gmch Power Management Graphic Power ManagementHub Interface to ICH4-M Intel 854 Chipset system block diagram Native Graphic mode Package Terms and Descriptions TerminologyTerm Description ICH4-M Reference Documents Reference DocumentsDocument Location Intel 82854 Graphics Memory Controller Hub Gmch System Architecture Intel 82854 Gmch Processor Host Interface Gmch System Memory InterfaceDDR Sdram Memory Capacity Technology Width Graphics Features Display FeaturesGmch Analog Display Port Gmch Integrated DVO Ports Hub Interface Address Decode Policies Gmch Clocking Intel 82854 Gmch Interface ClocksRatio Bytes MB/s System Interrupts Notation Description Buffer Description Host Interface Signals Host Interface Signal Descriptions DRDY# HIT#HITM# HLOCK# RS20# RS20# Response type DDR Sdram Interface DDR Sdram Interface DescriptionsSRAS# SCAS# Hub Interface Signals Hub Interface Signals Clocks Display Power Management Signaling This signal is used only DpmsDAC Clocking Drefclk Digital Video Output B Dvob Port Signal Descriptions Internal Graphics Display SignalsDigital Video Output B Dvob Port Digital Video Output C Dvoc Port Signal Descriptions Digital Video Output C Dvoc Port Analog CRT Display Signal Descriptions Dvob and Dvoc Port Common Signal DescriptionsAnalog CRT Display General Purpose Input/Output Signals Gpio Signal Descriptions Voltage References, PLL Power Voltage References, PLL Power Hlrcomp PswingHlvref Vcchl Device Number Assignment Conceptual Overview of the Platform Configuration StructureGmch Function Bus #0, Device# Nomenclature for Access Attributes Nomenclature for Access Attributes Routing Configuration Accesses Standard PCI Bus Configuration MechanismPCI Bus #0 Configuration Mechanism Primary PCI and Downstream Configuration Mechanism Default Value upon ResetRegister Definitions Reserved Bits Configaddress Configuration Address Register I/O Mapped Registers Bit Descriptions Reserved Configdata Configuration Data Register Configuration Data Register VGA I/O Mapped Registers VGA I/O Mapped Register ListIndex Data Registers Name Function Read @ Write @ Register Name Default Value Access Gmch Configuration Space Device #0, Function#0End Attbase Did Device Identification Register VID Vendor Identification RegisterBit Descriptions 150 Pcicmd PCI Command Register = Serr message is not generated by the Gmch for Device #0 PCI Status Register RID Register Identification Subc Sub Class Code Register HDR Header Type Register BCC Base Class Code RegisterSvid Subsystem Vendor Identification Register SID Subsystem Identification Register Capptr Capabilities Pointer Register Capid Capabilities Identification Register Device #0 Capability ID Rrbar Access Enable-R/W GMC Gmch Miscellaneous Control Register Device #0MDA Present MDAP-R/W VGA GGC Gmch Graphics Control Register Device #0 Reserved Device #2 Function #1 Enable/DisableBit Fdhc Fixed Dram Hold Control Register Device #0 Dafc Device and Function Control Register Device #0Bit Description Attribute Bit Assignment 17 PAM60 Programmable Attribute Map Register Device #0Bits 7 Bits 6 Bits 5 Bits 4 Description Reserved PAM Registers PAM Registers and Associated System Memory Segments DOS Application Area 00000h-9FFFhVideo Buffer Area A0000h-BFFFFh Expansion Area C0000h-DFFFFh System Bios Area F0000h-FFFFFh Extended System Bios Area E0000h-EFFFFhSmram System Management RAM Control Register Device #0 Esmramc Extended System Management RAM Control Device #0 Errsts Error Status Register Device #0 Errcmd Error Command Register Device #0 Smicmd SMI Error Command Register Device #0 Bit Description Reserved Scicmd SCI Error Command Register Device #0 Reserved SCI on Multiple-bit ECC ErrorSCI on Single-bit ECC Error SCI on Gmch Thermal Sensor Trip Reserved On Die Termination ODT Gating Disable Reserved FSB Data Bus Power Management ControlC2 state Gmch FSB Interface Power Management Control Shic Secondary Host Interface Control Register Device #0 HEM Host Error Control, Status, and Observation Device #0 DRB VID Vendor Identification Register Pcicmd PCI Command Register Pcists PCI Status Register RID Revision Identification Register Device. Reads and Writes to this location have no effect DRB Dram Row 03 Boundary Register Device #0 DRA Dram Row Attribute Register Device #0 DDR Internal Write to Read Command delay tWTR DDR Write Recovery time tWRDRT Dram Timing Register Device #0 Examples of usage Encoding CK between RD and WR commands Back To Back Read-Read commands spacing DDR, different RowsEncoding CK between RD and RD commands Refresh Cycle Time tRFC Activate to Precharge delay tRAS, MIN Activate to Precharge delay tRAS, MAXReserved CAS# Latency tCL PCEn Page Close Enable TC Timer Control PDEn23 CS# Signal Drive ControlDynamic Memory Interface Power Management Rcven DLL shutdown disable Power State S1/S3 Refresh Control DRC Dram Controller Mode Register Device #0 Ddim DDR Sdram Data Integrity Mode 000 001010 011 For Double Data Rate DTC Dram Throttling Control Register Device #0 DDR Sdram Throttle Mode Tmode Wttc 2724 Thermal Power Throttle Control fields Enable High Priority Stream Throttling Enable Hpllcc Did Device Identification Register Pcicmd PCI Command Register Pcists PCI Status Register Subc Sub-Class Code Register ID Subsystem Identification Register Hpllcc Hpll Clock Control Register Device #0 Hpll VCO Change Sequence Initiate Bit Straps Read GFX Core HPLLCC20DVO Port CRT Port Rate Register Name Regs VID Vendor Identification Register Device #2 Did Device Identification Register Device #2 Pcicmd PCI Command Register Device #2 Pcists PCI Status Register Device #2 RID Revision Identification Register Device #2 MLT Master Latency Timer Register Device #2 CC Class Code Register Device #2CLS Cache Line Size Register Device #2 Base Class Code Basec 03=Display controller Bit Description Master Latency Timer Count Value RO Prefetchable Memory-RO Enable prefetchingHDR Header Type Register Device #2 Gmadr Graphics Memory Range Address Register Device #2 Mmadr Memory Mapped Range Address Register Device #2 Iobar I/O Base Address Register Device #2Prefetchable Memory-RO Prevents prefetching Memory / IO Space-RO Svid Subsystem Vendor Identification Register Device #2 Romadr Video Bios ROM Base Address Registers Device #2SID Subsystem Identification Register Device #2 Intrpin Interrupt Pin Register Device #2 Intrline Interrupt Line Register Device #2Mingnt Minimum Grant Register Device #2 Auxiliary Power Source Hardwired to Pmcap Power Management Capabilities Register Device #2Maxlat Maximum Latency Register Device #2 Pmcs Power Management Control/Status Register Device #2 Bits10 Power State System Memory Address Ranges Simplified View of System Address Map DOS Compatibility Area Detailed View of System Address Map System Memory Segments and Their Attributes DOS Area 000000h-09FFFFhLegacy VGA Ranges 0A0000h-0BFFFFh Compatible Smram Address Range 0A0000h-0BFFFFh Extended System Bios Area 0E0000h-0EFFFFh System Bios Area 0F0000h-0FFFFFhExtended System Memory Area Monochrome Display Adapter MDA Range 0B0000h 0B7FFFh 1 15 MB-16 MB Window Pre-allocated System MemoryPre-allocated System Memory Attributes Comments Extended Smram Address Range Hseg and Tseg HsegTseg Dynamic Video Memory Technology Dvmt High Bios Area FFE00000h -FFFFFFFFh PCI Memory Address Range Top of Main System Memory to 4 GB SMM Space Restrictions System Management Mode SMM Memory RangeSMM Space Definition 5 I/O Address Space System Memory ShadowingSMM Space Transaction Handling Gmch Decode Rules and Cross-Bridge Address Mapping PCI I/O Address Mapping Hub Interface Accesses to Gmch that Cross Device Boundaries Hub Interface Decode Rules Accesses to Gmch that Cross Device Boundaries Cycles Initiated Using PCI ProtocolInterface Decode Rules Host Interface Overview Dynamic Bus InversionSystem Bus Interrupt Delivery Relation of DBI Bits to Data Bits System Memory Organization and Configuration Configuration Mechanism for DDR DIMMsSystem Memory Interface Upstream Interrupt Messages DDR Sdram Performance Description System Memory Register ProgrammingData Bytes on DDR Dimm Used for Programming Dram Registers Byte Function Integrated Graphics Overview 1 3D/2D Instruction Processing Setup Engine 2 3D EngineViewport Transform and Perspective Divide 2.3 3D Primitives and Data Formats Support Backface Culling Scan ConverterTexture Engine Perspective Correct Texture Support Anti-Aliasing Texture ChromakeyTexture Map Filtering Raster Engine Multiple Texture CompositionCubic Environment Mapping Bump Mapping Texture Map Blending Combining Intrinsic and Specular Color ComponentsColor Shading Modes Color Dithering Color Buffer Formats Destination Alpha Alpha BlendingDepth Buffer 4 2D Engine Stencil BufferProjective Textures 4.1 256-Bit Pattern Fill and BLT Engine Hardware Cursor Plane Native Graphic Mode only Dual Display Usage Model Native Graphic Mode onlyPlanes and Engines Alpha Stretch BLT Overlay Plane Color Control Dynamic Bob and Weave Video Functionality MPEG-2 DecodingHardware Motion Compensation Sub-picture Support Internal Graphic Display Interface Pipe a Timing Generator Unit 1.2 H, V timing signals for active and blank timing Arib Support Parameters HSYNC/VSYNC Field Timing Interlaced Video Field display Blend FunctionInterlace support for Plane a graphics Arib 960 X 540 support Interlace support for Video Overlay Window DVO Control Data Bits Timing Register Switching Integrated Ramdac Analog Display Port CharacteristicsDDC Display Data Channel 146 D15343-003 Power and Thermal Management General Description of Supported CPU States General Description of Acpi States Overview Internal Thermal SensorHysteresis Operation External Thermal Sensor Input Usage Strapping Signals and Configuration Strapping ConfigurationPin Name Strap Description Configuration Type Buffer Type GST20 Intel 82854 Gmch Straps for Frequency/CPU ConfigurationFSB Freq DDR Freq Gfx Freq Core Vcc Ballout and Package Information Voltage Levels and Ball Out for Voltage Groups VCC/VSS Voltage GroupsName Voltage Level Ball out Row Column Signal Name Ballout Table 156 D15343-003 D15343-003 157 158 D15343-003 D15343-003 159 160 D15343-003 D15343-003 161 162 D15343-003 D15343-003 163 Intel 82854 Gmch Micro-FCBGA Package Dimensions Top View Package Mechanical Information Intel 82854 Gmch Micro-FCBGA Package Dimensions Side View Intel 82854 Gmch Micro-FCBGA Package Dimensions Bottom View