HP 8000 manual Real-Time Clock and Configuration Memory, Clearing Cmos

Page 43

System Support

4.4 Real-Time Clock and Configuration Memory

The Real-time clock (RTC) and configuration memory (also referred to as “CMOS”) functions are provided by the 82801 component and is MC146818-compatible. As shown in the following figure, the 82801 ICH10 component provides 256 bytes of battery-backed RAM divided into two 128-byte configuration memory areas. The RTC uses the first 14 bytes (00-0Dh) of the standard memory area. All locations of the standard memory area (00-7Fh) can be directly accessed using conventional OUT and IN assembly language instructions through I/O ports 70h/71h, although the suggested method is to use the INT15 AX=E823h BIOS call.

0Dh

Register D

0Ch

Register C

0Bh

Register B

0Ah

Register A

09h

Year

08h

Month

07h

Date of Month

06h

Day of Week

05h

Hours (Alarm)

04h

Hours (Timer)

03h

Minutes (Alarm)

02h

Minutes (Timer)

01h

Seconds (Alarm)

00h

Seconds (Timer)

82801

Extended Config.

Memory Area

(128 bytes)

Standard Config.

Memory Area

(114 bytes)

RTC Area (14 bytes)

FFh

80h

7Fh

0Eh

0Dh

00h

CMOS

Figure 4 4. Configuration Memory Map

A lithium 3-VDC battery is used for maintaining the RTC and configuration memory while the system is powered down. During system operation a wire-Ored circuit allows the RTC and configuration memory to draw power from the power supply. The battery is located in a battery holder on the system board and has a life expectancy of three or more years. When the battery has expired it is replaced with a CR2032 or equivalent 3-VDC lithium battery.

4.4.1 Clearing CMOS

The contents of configuration memory (including the Power-On Password) can be cleared by the following procedure:

1.Turn off the unit.

2.Disconnect the AC power cord from the outlet and/or system unit.

3.Remove the chassis hood (cover) and insure that no LEDs on the system board are illuminated.

4.On the system board, press and hold the CMOS clear button (switch SW50, colored yellow) for at least 5 seconds.

5.Replace the chassis hood (cover).

6.Reconnect the AC power cord to the outlet and/or system unit.

7.Turn the unit on.

To clear only the Power-On Password refer to section 4.5.1.

 

Technical Reference Guide

www.hp.com

4-9

Image 43
Contents December Technical Reference GuideTechnical Reference Guide Contents System Support Processor/Memory SubsystemInput/Output Interfaces Integrated Graphics Subsystem Power and Signal DistributionError Messages and Codes Index System BiosOnline Viewing IntroductionAbout this Guide Additional Information SourcesValues Serial NumberNotational Conventions Special NoticesAcronyms and Abbreviations Common Acronyms and AbbreviationsAcronym or Abbreviation Description Cmos CDSCGA CMCEscd EisaEPP EideLAN IPLIRQ ISAPata NvramODD PALSecam SdramSdvo SECURL UartUdma UdimmIntroduction Introduction System OverviewFeatures 1ODD Feature Differences by Form FactorArchitectural Differences by Form Factor System ArchitectureFunction HP Compaq 8000 Elite Business PC Architecture, Block diagram Components Function Intel Processor SupportChipset Chipset Components and FunctionalityComponent Name Function Support ComponentsSystem Memory Support Component FunctionsNetwork Interface Controller Mass StorageSerial Interface Universal Serial Bus InterfaceIntegrated Graphics Controller Graphics SubsystemAudio Subsystem Integrated Graphics Subsystem StatisticsParameter Operating Non-operating SpecificationsEnvironmental Specifications Factory Configuration HP ProtectTools Embedded SecurityParameter Usdt SFF CMT Power Supply Electrical SpecificationsPhysical Specifications Parameter ValueSystem Overview Processor/Memory Subsystem Architecture Processor/Memory SubsystemIntel Processor Overview Intel ProcessorsForm Processor Changing/UpgradingSupported Processors partial listing Highest ClockMemory Subsystem Channel a Channel B Socket Socket 2 Socket 4 Total Memory UpgradingMemory Mapping and Pre-allocation Memory Socket LoadingSystem Memory Map for maximum of 8 gigabytes PCI Bus Overview System SupportPCI 2.3 Bus Operation PCI Component Function # Device # Wired to PCI Component Configuration Access PCI BusPCI Bus Mastering Devices PCI Express Bus OperationSoftware/Driver Layer Transaction Protocol LayerLink Layer PCI Power Management SupportOption ROM Mapping PCI InterruptsPCI 2.3 Connector PCI ConnectorsPCI 2.3 Bus Connector Pinout PCIe Bus Connector Pinout PCIe ConnectorsMode Apic ModeSystem Resources InterruptsPCI Interrupt Distribution Direct Memory AccessClearing Cmos Real-Time Clock and Configuration MemorySecurity Functions Configuration Memory Cmos MapSystem Management Standard Cmos LocationsInterface Security Power-On / Setup PasswordSetup Password Cable Lock ProvisionAcpi Wake-Up Event System Wakes From Power ManagementSmart Cover Lock Optional Acpi Wake-Up EventsSystem Operational Status LED Indications System Status PowerLED Beeps Action RequiredSystem Status Thermal Sensing and CoolingSystem I/O Map Register Map and Miscellaneous FunctionsPort Function System I/O MapICH10 Functions Gpio FunctionsSIO Controller Functions Input/Output Interfaces Pin Description Pin Sata Connector PinoutSATA/eSATA Interfaces Sata interfaceESATA interface Optional eSATA Bracket/Cable AssemblyPin Signal Description DB-9 Serial Connector PinoutSerial Interface Parallel Interface Support Standard Parallel Port ModeEnhanced Parallel Port Mode Extended Capabilities Port ModeDB-25 Parallel Connector Pinout Parallel Interface ConnectorPin Signal Function Keyboard Interface Operation Keyboard/Pointing Device InterfaceData Keyboard/Pointing Device Interface ConnectorKeyboard/Pointing Device Connector Pinout Pointing Device Interface OperationICH10 USB Port Mapping USB ConnectorController Signals USB Connector Location all form factors Universal Serial Bus InterfaceUSB Color Code USB Connector PinoutUSB Cable Data USB Cable Length DataAudio Subsystem Audio Subsystem Functional Block DiagramHD Audio Link Bus HD Audio ControllerAudio Multistreaming ADC/DAC Audio SpecificationsHD Audio Subsystem Specifications Parameter Measurement10. LAN LED Indications Network Interface ControllerFunction Activity LED Speed LED Wake-On-LAN Support Power Management SupportAlert Standard Format Support Parameter Compatibility standard orprotocol NIC ConnectorNIC Specifications 11. NIC SpecificationsIntegrated Graphics Subsystem RGB Functional DescriptionGMA 4500 Memory Allocation Sdram Installed Maximum Memory AllocationDisplay Modes Resolution Maximum Refresh Rate Analog Digital MonitorIGC Standard 2D Display Modes Upgrading Analog Monitor Connector Monitor ConnectorsDB-15 Monitor Connector Pinout Pin Signal DisplayPort ConnectorIntegrated Graphics Subsystem Usdt Power Distribution Power and Signal DistributionUsdt 135-Watt Power Supply Unit Specifications SFF/CMT Power DistributionParameter CMT 320-Watt Power Supply Unit Specifications SFF 240-Watt Power Supply Unit SpecificationsPressed Power Button Results Power ControlPower Button Power Button ActionsPower LED Indications Condition Wake Up Events Power ManagementConsumption To S0 by Required System Power StatesPower Transition OS Restart State System ConditionCR1 +5 VDC LED Signal DistributionSystem Board Connector, Indicator, and Switch Designations Power and Signal Distribution System Bios Upgrading ROM FlashingChangeable Splash Screen Memory Detection and Configuration Boot FunctionsBoot Device Order Network Boot F12 SupportBoot Error Codes Boot Error CodesVisual power LED Audible speaker Meaning Client Management Functions Function ModeClient Management Functions INT15 System Form Factor System ID Temperature StatusSystem ID and ROM Type System ID NumbersType Data Smbios FunctionsManagement Engine Functions USB Legacy SupportBeeps Power LED Probable Cause Error Messages and CodesBeep/Power LED Codes Table A-1 Beep/Power LED CodesPower-On Self Test Post Messages Table A-2 Table A-2 Error Message Probable CauseTable A-3 System Error Messages Probable Cause System Error MessagesMessage Probable Cause Memory Error MessagesMemory Error Messages Table A-4Table A-5 Keyboard Error Messages Probable Cause Keyboard Error MessagesTable A-7 Video Graphics Error Messages Probable Cause Printer Error MessagesVideo Graphics Error Messages Table A-6 Printer Error Messages Probable CauseTable A-8 Diskette Drive Error Messages Probable Cause Diskette Drive Error MessagesTable A-9 Serial Interface Error Messages Probable Cause Serial Interface Error MessagesModem Communications Error Messages System Status Error Messages System Status Error MessagesTable A-11 Table A-12 Hard Drive Error Messages Probable Cause Hard Drive Error MessagesXx = 03, Hard drive read/write compare test Table A-13 Hard Drive Error Messages Probable Cause Table A-14 Video Graphics Error Messages Probable Cause Audio Error MessagesTable A-15 Audio Error Messages Probable Cause Table A-17 Network Interface Error Messages Probable Cause 17 DVD/CD-ROM Error MessagesNetwork Interface Error Messages DVD/CD-ROM Error MessagesTable A-18 Scsi Interface Error Messages Scsi Interface Error Messages 65xx-xx, 66xx-xxPointing Device Interface Error Messages 8601-xx Error Messages and Codes Numerics IndexIndex
Related manuals
Manual 6 pages 2.04 Kb Manual 62 pages 34.71 Kb Manual 18 pages 10.45 Kb Manual 15 pages 45.88 Kb Manual 4 pages 52.73 Kb