Port a Hex, 0092, This Bit Reserved | IBM 560E manual

System Control	Port A (Hex		0092)

Bit	Function

7–3	Reserved
2	Reserved (must be set to 0)
1	Alternate	gate	A20
0	Alternate	hot	reset

Figure

2-32. System Control Port A

(Hex

0092)

Bits

7–3

These

bits

are

reserved.

Bit

2

This

bit

is

reserved.

Bit

1

This

bit

is used to enable the ‘addressA20 )

20’ signal (

when

the

microprocessor is

in

the

real

address

mode.

When

this

bit

is A20set cannotto0, be used

in

real

mode

addressing. This

bit

is

set

to

0

during a

system

reset.

Bit 0 This bit provides an alternative method of resetting the system microprocessor. This alternative method

supports operating systems requiring faster operation than that provided on the IBM Personal Computer AT. Resetting the system microprocessor switches the microprocessor from protected mode to real address mode.

This

bit is set to 0 by either a system reset or a write

operation. When

a

write

operation

changes

this

bit

from

0

to

1, the ‘processor reset’ signal is

pulsed

after

the

reset has occurred. While the reset is

occurring,

the

latch

remains

set

so

that POST

can

read

this

bit.

If

the

bit

is set to 0, POST assumes that the

system

was

just

powered on. If the bit is

set

to

1,

POST

assumes

that

the

microprocessor

has

been

switched from

protected

mode

to

real

mode.

When

bit

0

is

used

to

reset

the

system

microprocessor

to

the real

mode,

use

the

following

procedure:

1. Disable all maskable and nonmaskable interrupts.

2. Reset the system microprocessor by writing a 1 to bit 0.

3.Issue a Halt instruction to the system microprocessor.

4.Reenable all maskable and nonmaskable interrupts.

2-28ThinkPad 560/560E System Board

Image 50

IBM 560E manual Port a Hex, 0092, This Bit Reserved

Contents

06J0536 S76H-7587-01 With Local 1997Any country Contents Index SystemSmapi NMI Bios Video Modes for the ThinkPad . Computer Preface Viii ThinkPad 560/560E Preface Acoustical Readings Power Supply Voltages Output Protection System Overview Submodel Byte DescriptionModel Clock Hex Describes Devices System Board Devices and FeaturesLists System Board devices and their features. PS/2 products by type number Controller Device Type560 Device controller Audio subsystem Subsystem System Board I/O Address Map Shows Address Map Part 2 of 2. System Board I/O Address Map Clock SpecificationsTo Figure List Specifications For Computer Physical Specifications Idle Acoustical ReadingsWAd Bels Output Voltage V dc Current a Power SupplyVoltages Output Protection Power Supply ConnectorNominal value Power Supply Voltage Sequencing Protection Battery PackAverage 14ThinkPad 560/560E System Overview Mask Register Hex 0070 RT/CMOS Data Register Hex 0071 Configuration Miscellaneous System FunctionsRAM Subsystem System Control Port On-chip cache Memory MicroprocessorCache Memory Operation Address Space Hex C0000-C7FFF is L1 cacheablecode for Read Operations. onlyIf Connector Keyboard/Mouse ConnectorSignals Current For Dc pin 4 is 0.5 a for both Scan Codes Hardware Interface Technical Reference Key Numbers for the 85-Key Keyboard Displayable Characters and Symbols For displayable characters and symbols that are keyable from Pin Signal Disk Drive External Connector Part 1 of 2 -Pin External Connector Pin Assignments Part 2 of 2 -Pin External Connector Pin Assignments Signal Type 720KB Diskette Drive and ControllerFormat Size Diskette Drive Connector Pin Signal Type RAM Subsystem MemoryROM Subsystem Starting Above Hex 100000 boundary Connector thatMapped System Board ThinkPad 11. Dimm Connector Pin Assignments Bytes Their Addresses RAM active When Power Supply Not Turned ListsRAM Bytes Bits HexBit Hex 0071 Operations 0These bits allow the selection of a divider output Bytes HexStatus Register a BitFunction BCD Status Register Hex 00BThis Bit Indicates Whether Binary-coded-decimal Status Register C Hex Status Register D Hex 00D Status Byte Hex Cmos RAM ConfigurationByte Hex 00E Hard Disk Installed Diskette DriveBits 7-4These bits indicate the diskette drive type Byte Hex 011 This byte defines the type Byte Hex 014 HardByte Hex 012 This Bits 5 Hex 017 018 LowBytes Hex 015 and Hex 031 RT/CMOS NMI Disabled. BeforeMiscellaneous System Functions and Ports Address Register. See When Set This Bit Enables Timer Gate When read, this bit toggles for each refresh requestWhen Set This Bit Enables Speaker Data 0061 This Bit Reserved Port a Hex0092 Power-On Password Selectable Drive-Startup Sequence Hardware Compatibility Error Codes 33 Part 1 of 2. Error Codes Error Code Subsystems Video Subsystem Video Modes Audio Subsystem Sound Blaster LCD Video SubsystemDisplaying Output Both LCD and monitor Displaying output on the LCD or both on the LCD and monitor Video ModesThinkPad 560E Displaying output on the monitor Colors Numeric Start Size Mum Pels 800×600 Format Address Box PagesAlpha Buffer Maxi Pels 800×600 Buffer BoxStart Size Line Audio Port SpecificationsAudio Subsystem Sound Blaster Support Function System board has two 68-pin Specification VersionSubsystem III Pcmcia Standards and Specifications Current +for5V Dc±5% is For each Slot Total Both Slots Pin AssignmentsShows Pin Assignments For Pcmcia slots 10ThinkPad 560/560E Subsystems Set Power Get PowerMode BL=00h. . . . . . . . A-.27 Get Timer Request System Hibernation. . . . . . . . . . . . . A-.52 Power Management What is Smapi BIOS?System Configuration System Information Bios 16-bit/32-bit Protected Mode Entry Point This area identifies the Bios service level defined belowReal Mode Entry Point Information Word Parameter Structure Smapi BiosCalling Convention Input Field Sample in Assembler Language Sample in C Language Calling Convention Pseudo Code Assembler Language Language Return Codes Output Field ServiceGet System Identification CPU ID Information Control Unit Information Get System Sensor Get Video Information Get Refresh Rate Output Field System Configuration Service Output Field Set Display Device Get Pointing Device Set Pointing Device Input Field Support Mode BL=00h Get 28ThinkPad 560/560E Smapi Bios Get Timer Control 30ThinkPad 560/560E Smapi Bios Set Timer Control Event Bit Definition Condition Set System Event Get System Event Set System Event Condition Get System Event Condition 38ThinkPad 560/560E Smapi Bios Get System Set System Get Standby Timer Set Standby Get Hibernation Set Hibernation Get System Event Condition 46ThinkPad 560/560E Smapi Bios Get System Resume Set System Resume Timer 50ThinkPad 560/560E Smapi Bios Request System 52ThinkPad 560/560E Smapi Bios Samples Data Structure Parameters Byte SMBHDRSIG4 Input Parameter Typedef struct Function Declaration Installation Check Biosseg Find Smapi Head Word Smbhdrroffset Pfsmbheaderreal Bios Call Bit Protected Mode Word GetSystemID Corporation Columbus IBMDirector Licensing Thornwood 10594 Publication, are Trademarks of other companies as follows TrademarksFollowing terms, denoted by a double asterisk ** in this Index Configuration Low High Expansion Microprocessor Registers API Smapi IBM