SMRAMCache SMCACHE-RO. Hardwired to | Intel 845 guide

Register Description

R

3.5.24ESMRAMC—Extended System Mgmt RAM Control Register (Device 0)

Address Offset:	9Eh
Default Value:	38h
Access:	RO, R/W, R/WC, R/W/L
Size:	8 bits

The Extended SMRAM register controls the configuration of Extended SMRAM space. The Extended SMRAM (E_SMRAM) memory provides a write-back cacheable SMRAM memory space that is above 1 MB.

Bit	Description

7	H_SMRAM_EN (H_SMRAME)—R/W/L.Controls the SMM memory space location (i.e., above 1
	MB or below 1 MB). When G_SMRAME is 1 and H_SMRAME this bit is set to 1, the high
	SMRAM memory space is enabled. SMRAM accesses from FEDA_0000h to FEDB_FFFFh are
	remapped to DRAM address 000A0000h to 000BFFFFh.
	Once D_LCK is set, this bit becomes read only.

6	E_SMRAM_ERR (E_SMERR)—R/WC.
	0 = The software must write a 1 to this bit to clear it.
	1 = This bit is set when host accesses the defined memory ranges in Extended SMRAM (High
	Memory and T-segment) while not in SMM space and with the D-OPEN bit = 0.

5	SMRAM_Cache (SM_CACHE)—RO. Hardwired to 1.

4	SMRAM_L1_EN (SM_L1)—RO. Hardwired to 1.

3	SMRAM_L2_EN (SM_L2)—RO. Hardwired to 1.

2:1	TSEG_SZ[1-0](T_SZ)—R/W.Selects the size of the TSEG memory block if enabled. This
	memory is taken from the top of system memory space (i.e., TOM – TSEG_SZ), which is no
	longer claimed by the memory controller (all accesses to this space are sent to the hub interface
	if TSEG_EN is set). This field decodes as follows:
	00 = (TOM–128 KB) to TOM
	01 = (TOM–256 KB) to TOM
	10 = (TOM–512 KB) to TOM
	11 = (TOM–1 MB) to TOM
	Once D_LCK is set, this bit becomes read only.

0	TSEG_EN (T_EN)—R/W/L.Enabling of SMRAM memory (TSEG, 128 KB, 256 KB, 512 KB or
	1 MB of additional SMRAM memory) for Extended SMRAM space only. When G_SMRAME =1
	and TSEG_EN = 1, the TSEG is enabled to appear in the appropriate physical address space.
	Once D_LCK is set, this bit becomes read only.

64	Intel® 82845 MCH for SDR Datasheet

Image 64

Intel 845 manual ESMRAMC-Extended System Mgmt RAM Control Register Device, SMRAMCache SMCACHE-RO. Hardwired to

Contents

Intel 845 Chipset 82845 Memory Controller Hub MCH for SDR Document Number Intel 82845 MCH for SDR Datasheet Contents Register Device SMLT1-Secondary Master Latency Timer Register Device System Management Mode SMM Memory Range 103PMBASE1-Prefetchable Memory Base Address PMLIMIT1-Prefetchable Memory Limit Address 114 115117 118 Tables Revision History Revision Description Date Intel 82845 MCH Features System Block Diagram General Terminology Terminology and NotationsTerm Description Data Type Notation Number Format NotationData Type Size Number Format Notation Example Reference Documents Document Intel 845 Chipset System Architecture Intel 82845 MCH Overview System Bus Error Checking System Bus Interface System Memory Interface AGP InterfaceMemory Capacity Technology SDR PC133 Hub Interface Intel MCH ClockingIntel MCH Clock Ratio Table Interface Speed Processor Bclk Powerdown Flow System Interrupts Signal Description Intel MCH Simplified Block Diagram System Bus Signals Signal Name Type DescriptionDBIx# Data Bits Strobe Address Bits Strobe Data Bits RS20 Response Type Hub Interface Signals SDR Sdram Interface SignalsSdram Column Address Strobe SCAS# is used with SRAS# AGP Interface Signals AGP Addressing SignalsDuring SBA Operation Not Used During FRAME# Operation Not Used AGP Flow Control Signals AGP Status SignalsRBF# WBF# AGP Strobes Signals 5 AGP/PCI Signals Command/Byte Enable Parity Clocks, Reset, and Miscellaneous Signals BclkBCLK# Cmos RSTIN# AGTL+ Bus Termination Voltage Inputs These pins provide Voltage Reference and Power SignalsSystem Memory Rcomp Reset States During Reset Signal NameState System Bus Interface Register Description Register Terminology Intel MCH Internal Device Assignments PCI Bus Configuration Space AccessMCH Function Bus 0, Device # Standard PCI Bus Configuration Mechanism Routing Configuration Accesses CONFADDR-Configuration Address Register I/O Mapped Registers Configuration Enable Cfge Bit Descriptions CONFDATA-Configuration Data Register Address 0CFCh Default Value 00000000h Access Size BitsMemory-Mapped Register Space Memory-mapped Register Address Map DRAMWIDTH-DRAM Width Register Address Offset 2Ch Default Value 00h Access Size BitsRow Parameters SDR Clocks Affected DQCMDSTR-Strength Control Register SDQ and CMD Signal Groups CKESTR-Strength Control Register Scke Signal Group Memory Address Offset 31h Default Value 00h Access Size Bits CSBSTR-Strength Control Register SCS# Signal Group Memory Address Offset 32h Default Value 00h Access Size Bits CKSTR-Strength Control Register Clock Signal Group Memory Address Offset 33h Default Value 00h Access Size Bits RCVENSTR-Strength Control Register Rcvenout Signal Group Memory Address Offset 34h Default Value 00h Access Size Bits Intel MCH Configuration Space Device Address Register Register Name Default AccessHost-Hub Interface Bridge Device Registers Device Value EAP FdhcSmram Esmramc VID-Vendor Identification Register Device DID-Device Identification Register DeviceBit Description Bit Description PCICMD-PCI Command Register Device Address Offset 04-05h Default 0006h Access Size Bits PCISTS-PCI Status Register Device Address Offset 06-07h Default Value 0090h AccessSize Bits Address Offset 0Ah Default Value 00h Access Size Bits Address Offset 0Bh Default Value 06h Access Size BitsRID-Revision Identification Register Device SUBC-Sub-Class Code Register Device MLT-Master Latency Timer Register Device Address Offset 0Dh Default Value 00h Access Size BitsAddress Offset 0Eh Default 00h Access Size Bits Bit Description Hardwired to 00h. Writes have no effect APBASE-Aperture Base Configuration Register Device Offset 10-13h Default 00000008h Access Size Bits SID-Subsystem Identification Device SVID-Subsystem Vendor Identification DeviceCAPPTR-Capabilities Pointer Device AGPM-AGP Miscellaneous Configuration Register Device Address Offset 51h Default Value 00h Access Size BitsOffset 60-67h DRB0-DRB7 Default 00h Access Size Bits 15 DRB07-DRAM Row Boundary Registers Device Offset 70-73h DRA0-DRA3 Default 00h Access Size Bits DRA-DRAM Row Attribute Registers Device Corresponding row Offset 78-7Bh Default 00000010h Access Size Bits DRT-DRAM Timing Register Device DRC-DRAM Controller Mode Register Device Offset 7C-7Fh Default 00000000h Access Size Bits = Normal operation EAP-Error Address Pointer Register Device DERRSYN-DRAM Error Syndrome Register DeviceAddress Offset 86h Default Value 00h Access Size Bits 21 PAM06-Programmable Attribute Map Registers Device Bits 7 Bits 6 Bits 5 Bits 4 Description PAM Register Attributes PAM6 PAM5 PAM4 PAM3 PAM2 PAM1 PAM0 DOS Application Area 00000h-9FFFh PAM Reg Attribute Bits Memory Segment Comments Offset Address Offset 97h Default Value 00h Access Size Bits FDHC-Fixed Dram Hole Control Register Device Global Smram Enable GSMRAME-R/W/L SMRAM-System Management RAM Control Register Device SMRAMCache SMCACHE-RO. Hardwired to SMRAML1EN SML1-RO. Hardwired toSMRAML2EN SML2-RO. Hardwired to ESMRAMC-Extended System Mgmt RAM Control Register Device ACAPID-AGP Capability Identifier Register Device AGPSTAT-AGP Status Register Device This register reports AGP device capability/status AGPCMD-AGP Command Register Device SideBand Address Enable SbaenAGP Enable Agpen Fast Write Enable Fwen AGPCTRL-AGP Control Register Device Data Rate 4x Override APSIZE-Aperture Size Device Address Offset B4h Default Value 00h Access Size BitsAperture Size ATTBASE-Aperture Translation Table Base Register Device AMTT-AGP Interface Multi-Transaction Timer Register Device Address Offset BCh Default Value 00h Access Size Bits LPTT-AGP Low Priority Transaction Timer Register Device Address Offset BDh Default Value 00h Access Size Bits Address Offset C4-C5h Default Value 0100h Access Size Bits TOM-Top of Low Memory Register Device Offset C6-C7h Default 0000h Access Size Bits MCHCFG-MCH Configuration Register DeviceApic Memory Range Disable APICDIS-R/W ERRSTS-Error Status Register Device Address Offset C8-C9h Default Value 0000h Access Size Bits ERRCMD-Error Command Register Device Address Offset CA-CBh Default Value 0000h Access Size BitsSingle-bit Dram ECC Error Flag Dserr Serr on Non-DRAM Lock Lckerr Serr on AGP Access Outside of Graphics Aperture Oogfserr Serr on Invalid AGP Access IaafserrSerr Multiple-Bit Dram ECC Error Dmerrserr Serr on Single-bit ECC Error Dserr SMICMD-SMI Command Register Device SCICMD-SCI Command Register DeviceAddress Offset CC-CDh Default Value 0000h Access Size Bits Address Offset CE-CDh Default Value 0000h Access Size Bits Address Offset E4h Default Value 0104A009h Access Size Bits Address Offset DE-DFh Default Value 0000h Access Size BitsSKPD-Scratchpad Data Register Device Address Symbol Name Default Access Bridge Registers Device 2 DID1-Device Identification Register Device 1 VID1-Vendor Identification Register DeviceDrtc PCICMD1-PCI-PCI Command Register Device Address Offset 04-05h Default 0000h AccessParity Error Enable PERRE1-RO. Not Implemented Hardwired to Memory Access Enable MAE1-R/W Address Offset 06-07h Default Value 00A0h Access Detected Parity Error DPE1-RO. Not Implemented Hardwired toSignaled System Error SSE1-R/WC PCISTS1-PCI-PCI Status Register Device Address Offset 0Ah Default Value 04h Access Size Bits 5 RID1-Revision Identification Register DeviceSUBC1-Sub-Class Code Register Device 7 BCC1-Base Class Code Register Device 8 MLT1-Master Latency Timer Register Device Offset 0Eh Default 01h Access Size BitsOffset 18h Default 00h Access Size Bits 9 HDR1-Header Type Register Device Offset 19h Default 00h Access Size Bits Offset 1Ah Default 00h Access Size BitsSBUSN1-Secondary Bus Number Register Device SUBUSN1-Subordinate Bus Number Register Device SMLT1-Secondary Master Latency Timer Register Device Address Offset 1Bh Default Value 00h Access Size Bits IOBASE1-I/O Base Address Register Device IOLIMIT1-I/O Limit Address Register Device Address Offset 1E-1Fh Default Value 02A0h Access Detected Parity Error DPE1-R/WCSSTS1-Secondary PCI-PCI Status Register Device Received Master Abort Status RMAS1-R/WC Address Offset 20-21h Default Value FFF0h Access Size Bits Address Offset 22-23h Default Value 0000h Access Size BitsMBASE1-Memory Base Address Register Device MLIMIT1-Memory Limit Address Register Device Address Offset 24-25h Default Value FFF0h Access Size Bits Address Offset 26-27h Default Value 0000h Access Size BitsPMBASE1-Prefetchable Memory Base Address Register Device PMLIMIT1-Prefetchable Memory Limit Address Register Device Address Offset 3Eh Default 00h Access BCTRL1-PCI-PCI Bridge Control Register Device Address Offset 40h Default Value 00h Access Size Bits ERRCMD1-Error Command Register DeviceSerr on Receiving Target Abort Serta Write Thermal Management Mode WTMMode Address Offset 50-57h Default Value 00h Access Size BitsDWTC-DRAM Write Thermal Management Control Register Device Read Thermal Management Mode RTMMode DRTC-DRAM Read Thermal Management Control Register Device This page is intentionally left blank Memory Address Ranges Addressable Memory Space DOS Compatible Area Address Map VGA and MDA Memory Space Vgab PAM Memory Spaces ISA Hole Memory Space Tseg SMM Memory Space Ioapic Memory SpaceSystem Bus Interrupt Apic Memory Space High SMM Memory Space AGP Memory Address Ranges AGP Aperture Space Device 0 BARAGP Memory and Prefetchable Memory Hub Interface Subtractive Decode System Management Mode SMM Memory Range AGP Dram Graphics Aperture SMM Space Definition SMM Space RestrictionsSMM Space Address Ranges Tseg Intel MCH Decode Rules and Cross-Bridge Address Mapping I/O Address SpaceHub Interface Decode Rules Cycles Initiated Using AGP FRAME# Protocol AGP Interface Decode Rules Dynamic Bus Inversion System BusDBI30# System Bus Interrupt Delivery Upstream Interrupt Messages Memory Organization and Configuration Supported Dimm ConfigurationsSystem Memory Interface Single Data Rate SDR Sdram Interface Overview Data Bytes on Dimm Used for Programming Dram Registers Byte Function Memory Address Translation and Decoding Address Translation and Decoding Dram Performance Description AGP Interface OverviewAGP Target Operations BE30# MCH Host Bridge Command Encoding Response as PCIx Target AGP Signal Levels AGP Transaction Ordering4 4x AGP Protocol Fast Writes AGP FRAME# Transactions on AGP PCI Command BE30# Intel MCH EncodingData Rate Control Bits 116 Power and Thermal Management Processor Power State Control Intel MCH Clocking Intel MCH System Reset and Power SequencingSleep State Control Power Characteristics Power CharacteristicsAbsolute Maximum Ratings Absolute Maximum Ratings Signal Groups Signal GroupsSignal Signal Type Signals BCLK, BCLK# DC Characteristics DC Characteristics Intel 82845 MCH for SDR Datasheet 123 124 Ballout and Package Information Intel 82845 MCH Ballout Diagram Top View-Left Side Intel 82845 MCH Ballout Diagram Top View-Right Side Signal Name Ball # HADSTB0# HADSTB1# AA2AB5 AA5 130 SBA4 SBA5SBA6 SBA7 132 VSSA1 VSSA0 Intel MCH FC-BGA Package Dimensions Top and Side View Package Mechanical Information Intel MCH FC-BGA Package Dimensions Bottom View 136 XOR Test Mode Initialization XOR Tree Chain Chain 0 Ball Element # Signal Name Initial Logic XOR ChainsXOR Chain AE6 HDSTBP1# SCK10 Chain 1 Ball Element # Signal Name Initial Logic SDQ22 Chain 2 Ball Element # Signal Name Initial Logic LevelSDQ65 SBCS1 Chain 3 Ball Element # Signal Name Initial Logic LevelSDQ64 Chain 4 Ball Element # Signal Name Initial Logic Level Adstb Chain 5 Ball Element # Signal Name Initial Logic Level Gado Intel 82845 MCH for SDR Datasheet 145 Chain 6 Ball Element # Signal Name Initial Logic Level AH9 DBI2# Chain 7 Ball Element # SDR Ball name Initial Logic Level AE6 HDSTBN1#AD5 DBI0# AD4 HDSTBN0# 148