Figure 21. Compaq iPAQ Desktop Personal Computers
This chapter includes the following topics:
Features and options (2.2) page 2-2
Mechanical design (2.3) page 2-4
System architecture (2.4) page 2-10
Specifications (2.5) page 2-20
2-1
Compaq iPAQ Series of Desktop Personal Computers
Second Edition - February 2001
Chapter 2 System Overview
2 .2 FEATURES AND OPTIONS
This section describes the standard features and available options.
2.2.1 STANDARD FEATURES
The following standard features are available on all models:
Celeron or Pentium III processor
Two DIMM sockets for system memory
AC'97 audio subsystem with front panel microphone and headphone jacks
MultiBay w/hot-swap support
Hard drive fault prediction
Two USB ports on front panel
Network interface controller
VGA analog output (1600 x 1200 max resolution)
APM 1.2 power management support
Plug 'n Play compatible (with ESCD support)
Intelligent Manageability support
Energy Star compliant
Security features including:
Setup and power-on passwords
DriveLock for MultiBay hard drive
I/O interface disabling
Administrator password
Network service boot
Asset tracking tag
UUID
Cable lock provision
Compaq Easy-Access keyboard w/Windows support
Mouse
90-watt power supply
Table 2-1 shows the differences in features between the iPAQ 1.0, 1.2, and 2.0 models:
2-2 Compaq iPAQ Series of Desktop Personal Computers
Second Edition February 2001
Technical Reference Guide
Table 2-1. iPAQ Standard Feature Difference Matrix
Table 2-1.
iPAQ Standard Feature Difference Matrix
iPAQ 1.0 iPAQ 1.2 iPAQ 2.0
Processor Celeron Pentium Pentium Celeron Pentium
Processor Speed (MHz) 500 500 733 700 866
Chipset 810E 810E 810E 815E 815E
System Memory:
DIMM type PC100 PC100 PC100 PC133 PC133
DIMM technology (Max) 128Mb 128Mb 128 Mb 256 Mb 256 Mb
Max amount supported 256 MB 256 MB 256 MB 512 MB 512 MB
4-MB Display cache No Yes Yes Optional Yes
Hard Drive Interface UATA/66 UATA/66 UATA/66 UATA/100 UATA/100
Multibay eject button At rear At rear At rear At front At front
Rear panel USB ports 3 [1] 3 [1] 3 [1] 4 4
Serial port 1 [2] 1 [2] 1 [2] 1 [2] 1 [2]
Parallel port 1 [2] 1 [2] 1 [2] 1 [2] 1 [2]
NOTES:
Legacy models ship with PS/2 keyboard and mouse. Legacy-free models ship with
USB keyboard and mouse.
[1] Legacy-free models only.
[2] Legacy models only
2.2.2 OPTIONS
The following items are available as options for all models and may be included in the standard
configuration of some models:
Memory: 32-MB DIMM (non-ECC)
64-MB DIMM (non-ECC)
128-MB DIMM (non-ECC)
256-MB DIMM (non-ECC) (iPAQ 2.0 only)
4-MB Display Cache module (iPAQ 2.0 only)
Hard drives/accessories: 4.3 or 8.4 GB UATA/66 hard drive
10 GB UATA/100 hard drive (iPAQ 2.0 only)
Multibay hard drive adapter
Multibay 250 Zip drive
I/O Expansion: Legacy Module (iPAQ 2.0 only)
Communications: USB 56K V.92 Modem
USB 802.11b Adapter
Security: Security bar (iPAQ 2.0 only)
MultiBay drives: 24x CD-ROM drive
8x DVD-ROM drive
4/4/20x CD-RW drive
Super Disk LS-120 Power Drive
2-3
Compaq iPAQ Series of Desktop Personal Computers
Second Edition - February 2001
Chapter 2 System Overview
2 .3 MECHANICAL DESIGN
The Compaq iPAQ Internet Device uses a minitower form factor featuring a smaller footprint and
reduced height than previous minitowers, allowing easy floor or desktop positioning. Commonly
used audio and USB connections are accessible from the front panel.
NOTE: The following information is primarily for identification purposes only. For
detailed information on servicing these systems refer to the applicable service guides.
Most components of iPAQ 1.0/1.2 and 2.0 systems are not inter-changeable.
2.3.1 CABINET LAYOUTS
2.3.1.1 Front Views
1 1
2 2
3 3
4 4
5
9
6 6
7 5
8 8
7
iPAQ 2.0
iPAQ 1.0/1.2
Item Description
1 Power Button
2 Power LED
3 Hard drive activity LED
4 MultiBay device bay (accepts 5.25"/12.7 mm storage device)
5 Microphone In Jack
6 Headphone Out Jack
7 USB port (through-Hub)
8 USB port (through-Hub)
9 Multibay device eject button
Figure 22. Compaq iPAQ Desktops, Front Views
2-4 Compaq iPAQ Series of Desktop Personal Computers
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Technical Reference Guide
2.3.1.2 Rear Views
2
2 1
1
4
4
3
3
6
6
5
5 9b
8
9b
7 10
10
12
9a
11
13
13
14
14
IPAQ 1.0/1.2 Legacy IPAQ 1.0/1.2 Legacy-Free
16
6
9a [1] 9a
9b 9b
3 4
11
12 1
5
2
8
7
15
14
Legacy Module for
iPAQ 2.0 13
iPAQ 2.0
Item Description Item Description
1 Audio line output 2 Audio line input
3 Network activity LED indicator 4 Network I/F jack
5 Network speed LED indicator 6 VGA monitor connector
7 Parallel I/F connector 8 Serial I/F connector
9 USB port: a) direct, b) through-hub 10 MultiBay device eject button
11 PS/2 mouse connector 12 PS/2 keyboard connector
13 AC line in connector 14 Line voltage select switch
15 Legacy module connector 16 Carrying depression
NOTE: [1] Dedicated-direct USB port.
Figure 23. Compaq iPAQ Desktops, Rear Views
2-5
Compaq iPAQ Series of Desktop Personal Computers
Second Edition - February 2001
Chapter 2 System Overview
2.3.2 CHASSIS LAYOUTS
2.3.2.1 iPAQ 1.0/1.2 CHASSIS LAYOUT
The internal assemblies of iPAQ 1.0/1.2 models are accessible from the right side of the system
unit. The right side (carbon-colored) cover features tool-less removal allowing quick access to the
DIMM sockets through an access opening and to the hard drive. Access to the system board and
processor requires removing the right chassis access panel. The multibay device is located on the
left side of the chassis and can be removed (using the eject button) without removing the left side
cover. Servicing the multibay board will, however, require removal of the left side cover.
2 3 4 5
1
6
10 9 8 7
Right Side Cover Removed Right Side Cover and
Left Side Cover Removed
Chassis Access Panel Removed
Item Description
1 Multibay device board
2 Multibay storage device
3 Access opening to DIMM sockets
4 Hard drive in 3.5" 1/3 height bay
5 Power button/LED board (PCA# 010647)
6 System board (PCA# 161014 or 161015)
7 Power supply assembly
8 Processor
9 Speaker
10 Audio and USB I/O board (PCA# 010650)
Figure 24. Compaq iPAQ 1.0/1.2 Desktop Chassis Layout
2-6 Compaq iPAQ Series of Desktop Personal Computers
Second Edition February 2001
Technical Reference Guide
2.3.2.2 iPAQ 2.0 CHASSIS LAYOUT
The internal assemblies of the iPAQ 2.0 model are accessible from both sides of the system unit.
Both side covers (carbon-colored) feature tool-less removal allowing quick access to serviceable
components such as DIMMs and hard drives.
1
2 6
3
4 7
8
5
9
10
Right Side Cover and
Left Side Cover Removed Right Side Cover Removed
Access Panel Removed
Item Description
1 Multibay storage device
2 Access hole to CMOS clear button
3 Access opening to DIMM sockets
4 Multibay device board (PCA #011059)
5 Hard drive in 3.5" 1/3 height bay
6 System board (PCA# 011010)
7 4-MB display cache module (PCA# 011044) (if installed)
8 Processor/heat sink assembly
9 Speaker
10 Power supply assembly
Figure 25. Compaq iPAQ 2.0 Chassis Layout
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Compaq iPAQ Series of Desktop Personal Computers
Second Edition - February 2001
Chapter 2 System Overview
2.3.3 SYSTEM BOARD LAYOUTS
Compaq iPAQ 1.0 and 1.2 systems use a FlexATX-type (9.0 x 7.5 inch) system board in one of
two variations; a legacy board or a legacy-free board (Figure 2-6).
1 2 3 4 5 1 2 3 4 5
22 22
6 6
21 21
7 7
7 7
20 20
8 8
9 9
19 19
10
11
12
13
18 18
17 16 15 17 16 15 14
Legacy PCA# 161014 Legacy-Free PCA# 161015
Item Description Item
1 USB ports 3 and 4 (front panel) header 12 USB ports 0, 1, 2 connectors
2 Battery 13 Dual PS/2 conn.: (mouse, keyboard)
3 BIOS ROM configuration jumper 14 Serial I/F header
4 Speaker connector 15 PGA370 processor socket
5 Audio microphone/headphone header 16 DIMM sockets
6 Audio line out jack 17 Processor (boxed) fan header
7 Audio line in jack 18 IDE (pri.) 40-pin connector
8 Network connector 19 IDE (sec.) 50-pin (multibay) connector
9 VGA monitor connector 20 Power button/LED indicator connector
10 Parallel I/F connector 21 CD audio header
11 Serial I/F connector 22 Power supply connector
NOTE:
Refer to Chapter 7 "Power and Signal Distribution" for header pinouts.
Figure 26. Compaq iPAQ 1.0/1.2 System Board Layouts
2-8 Compaq iPAQ Series of Desktop Personal Computers
Second Edition February 2001
Technical Reference Guide
All iPAQ 2.0 systems use a Compaq-proprietary system board (Figure 2-7).
1 2 3 4 5
6
19 7a
21 7b
18
8
17 9
10
16
20
11
15
14 13 12
PCA# 011010, Solder Side PCA# 011010, Component Side
Item Description
1 Power button
2 Battery
3 CMOS clear switch
4 Display cache module connector
5 Password enable jumper
6 Video graphics monitor connector
7 USB connector pairs: a) J111; b) J112
8 Network connector
9 Audio line in jack
10 Audio line out jack
11 Legacy module connector
12 PGA370 processor socket
13 DIMM sockets
14 Power supply connector
15 USB triple connector (center port not used)
16 Microphone in, Headphone out jacks
17 Speaker connector
18 Hard drive activity LED
19 Power LED
20 Hard drive connector (IDE primary)
21 Multibay board connector (IDE secondary)
Figure 27. Compaq iPAQ 2.0 System Board Layout
2-9
Compaq iPAQ Series of Desktop Personal Computers
Second Edition - February 2001
Chapter 2 System Overview
2 .4 SYSTEM ARCHITECTURE
The Compaq iPAQ Series of Desktop Personal Computers features Intel Celeron or Pentium III
processors. The iPAQ 1.0/1.2 models employ an architecture based on the Intel 810e chipset
while iPAQ 2.0 models are based on the Intel 815e chipset.
2.4.1 IPAQ 1.0/1.2 ARCHITECTURE
The architecture of iPAQ 1.0/1.2 models is based on the Intel 810e chipset with a Celeron or
Pentium III processor installed as standard. iPAQ 1.0 systems feature 500-MHz processors while
iPAQ 1.2 systems feature 733-MHz Pentium III processors. As indicated in the following table and
shown in Figure 2-8, two basic configurations are available:
Legacy-free with Celeron or Pentium III processor
Legacy with Celeron or Pentium III processor
Legacy-free systems provide five Universal Serial Bus (USB) ports for connecting peripherals
(including the supplied USB mouse and USB keyboard). Legacy light systems provide two USB
ports along with PS/2 ports for the supplied mouse and keyboard as well as parallel and serial
ports.
NOTE: A legacy-free iPAQ 1.0/1.2 system is upgradeable to become a legacy system
only by changing the system board.
All iPAQ 1.x systems use the 810E chipset. The 810E chipset includes the 82810E-DC100 GMCH
designed to support 100-MHz SDRAM and also integrates a 2D/3D Direct AGP graphics
controller. Pentium III-based systems come with an additional 4-MB display cache (soldered
down) to compliment the graphics controller.
The 810E chipset also includes an 82801 I/O Controller Hub (ICH) that provides two IDE
interfaces, two USB interfaces, and a PCI bus controller. The 82802 Firmware Hub (FWH)
component is loaded with Compaq BIOS. The iPAQ 1.0/1.2 features an AC'97 audio subsystem
with 5-watt amplifier and internal speaker. All iPAQ 1.0/1.2 systems feature a 90-watt power
supply. Table 2-2 lists differences between system architectures:
Table 2-2. iPAQ 1.0/1.2 Architectural Comparison
Table 2-2.
IPAQ 1.0/1.2 Architectural Comparison
IPAQ 1.0 IPAQ 1.2
Legacy-Free Legacy Legacy-Free Legacy
Processor Type Celeron Pentium Celeron Pentium Pentium Pentium
Processor Speed (MHz) 500 500 500 500 733 733
FSB Speed (MHz) 66 100 66 100 133 133
4-MB Display Cache? No Yes No Yes Yes Yes
Mouse/Keyboard Type USB USB PS/2 PS/2 USB PS/2
Serial port? No No Yes Yes No Yes
Parallel port? No No Yes Yes No Yes
# of USB ports 5 5 2 2 5 2
2-10 Compaq iPAQ Series of Desktop Personal Computers
Second Edition February 2001
Technical Reference Guide
Celeron or
Pentium III
Processor
66-/100-/133- MHz FSB
810E Chipset
Monitor
PC100
82810E-DC100
RGB Memory
GMCH
Bus SDRAM
SDRAM
Graphics
System
Cntlr.
Cntlr.
4-MB Memory
Display Cache
Hub Link USB Hub
Bus
USB USB USB USB USB
USB
Pri.
UATA/66 Port 0 Port 1 Port 2 Port 3 Port 4
I/F
IDE I/F
Hard Drive 82801
ICH
Sec.
MultiBay
IDE I/F
Device
LPC
Keyboard/
Bus
Mouse I/F
82802
LPC47B277 I/O Controller
FW H
Serial Parallel
Beep
I/F I/F
Audio
33-MHz
Audio AC'97
32-Bit PCI Bus
Subsystem Link Bus
82559
Ethernet Power
Controller Supply
LEGEND:
Legacy systems only.
Legacy-free systems only.
Pentium III-based systems only.
Figure 28. Compaq iPAQ 1.0/1.2 Architecture, Block diagram
Compaq iPAQ Series of Desktop Personal Computers 2-11
Second Edition - February 2001
Chapter 2 System Overview
2.4.2 IPAQ 2.0 ARCHITECTURE
The iPAQ 2.0 models feature an architecture based on the Intel 815E chipset with a 700-MHz
Celeron or 866-MHz Pentium III processor installed (Figure 2-9).
The 815E chipset includes the 82815 GMCH designed to control up to 512 megabytes of 133-
MHz (PC133) SDRAM and also integrates a 2D/3D Direct AGP graphics controller. Pentium III-
based systems come with a 4-MB display cache module installed to compliment the graphics
controller. Celeron-based systems may be upgraded by adding the 4-MB display cache module.
The 815E chipset also includes an 82801BA I/O Controller Hub (ICH2) that provides two IDE
controllers providing UATA/100 support, two USB controllers, a network interface controller, and
a PCI bus controller.
All iPAQ 2.0 systems provide six USB ports. Two USB ports are configured as direct ports, with
one direct port dedicated to a USB controller for maximum throughput operation. Four ports are
configured as "through-hub" ports.
An LPC47B357 I/O controller is embedded on the system board of all iPAQ 2.0 systems.
Functions supported by the I/O controller (serial, parallel, mouse and keyboard I/Fs) are available
when the legacy module is attached to the system, making it a legacy system. A legacy-free iPAQ
2.0 system may easily be converted to a legacy system by installing the legacy module, which
snaps into place at the rear of the unit.
NOTE: Legacy-free models ship with USB keyboards and USB mouse devices. Legacy
models (shipped with the legacy module installed) include PS/2 keyboards and mouse
devices.
The Firmware Hub (FWH) component (82802 or equivalent) is loaded with Compaq BIOS.
The iPAQ 2.0 features an AC'97 audio subsystem with 8-watt amplifier and internal speaker. The
audio system includes microphone and line inputs and headphone and line outputs.
All iPAQ 2.0 systems feature a 110-watt power supply.
2-12 Compaq iPAQ Series of Desktop Personal Computers
Second Edition February 2001
Technical Reference Guide
Celeron or
Pentium III
Processor
66-/100-/133- MHz FSB
815E Chipset
Monitor
PC133
82815
RGB Memory
GMCH
Bus SDRAM
SDRAM
Graphics
System
Cntlr.
Cntlr.
4-MB Memory
Display Cache
Module
Hub Link
Bus
Front Panel
USB USB Ports (2)
USB
Pri. Hub
UATA/100
I/F
IDE I/F
Hard Drive 82801BA Rear
ICH2 Panel
USB
Sec.
MultiBay USB Ports (4)
I/F
IDE I/F
Device
NIC
82802
FW H
LPC
Beep Bus Legacy
Audio
Module
NIC
LPC47B357
Audio AC'97 I/F
I/O Controller or
Subsystem Link Bus
PS/2 or
Keyboard/
Ports
Mouse I/F
COM
Serial
Port
I/F
Power
Supply
Parallel LPT
I/F Port
LEGEND:
Standard on Pentium III systems.
Standard on legacy systems.
Figure 29. Compaq iPAQ 2.0 Architecture, Block diagram
Compaq iPAQ Series of Desktop Personal Computers 2-13
Second Edition - February 2001
Chapter 2 System Overview
2.4.3 PROCESSORS
The Compaq iPAQ desktop series includes models based on Celeron and Pentium III processors.
These processors are backward-compatible with software written for the Pentium II, Pentium
MMX, Pentium Pro, Pentium, and x86 microprocessors. Both processor architectures include a
floating-point unit and first and secondary caches providing enhanced performance for multimedia
applications.
2.4.3.1 Celeron Processor
Select Compaq iPAQ systems use the Intel Celeron processor. The Celeron processor provides
economical performance and is compatible with software written for previous generation
processors such as Pentium II, Pentium MMX, Pentium, and x86 processors. Featuring a Pentium-
type core architecture, the Celeron processor integrates a dual-ALU CPU with a floating-point
unit, 32-KB first-level cache, and 128-KB second level cache, all of which operate at full
processing (CPU) speed. Celeron processors shipped with these systems provide the same level of
MMX/SSE support as Pentium III-based systems.
The Celeron processor uses a Flip-Chip (FC) PGA370 package with a heat sink.
2.4.3.2 Pentium III Processor
The Intel Pentium III processor provides maximum performance for Compaq iPAQs. The Pentium
III processor is compatible with software written for Celeron, Pentium II, Pentium MMX, Pentium,
and x86 processors.
The Pentium III processor core integrates a dual-ALU CPU with a floating-point unit and 32-KB
first-level cache operating at processing (CPU) speed. Featuring .18-micron technology, the
Pentium III processor features 256 kilobytes of secondary cache included on the CPU die and
operating at full processor speed.
The Pentium III processor includes MMX technology for enhanced multimedia performance. Also
included are 70 additional streaming SIMD extensions (SSE) for enhancing 3D graphics and
speech processing performance and a serial number function useful for asset tracking.
The Pentium III processor employed in these systems uses a Flip-Chip (FC) PGA370 package and
heat sink (Figure 2-10).
2-14 Compaq iPAQ Series of Desktop Personal Computers
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Technical Reference Guide
2.4.3.3 Processor Upgrading
All models of the Compaq iPAQ use the PGA370 zero-insertion force (ZIF) socket for processor
mounting as shown in Figure 2-10. The processor assembly includes a heat sink attached by a
retaining clip or bar. Replacing the processor requires removal of the heat sink followed by
removal of the processor. On iPAQ 2.0 systems, the heat sink is held in place by a retaining bar
with it's own locking handle.
CAUTION: Refer to section 3.2.2 (Chapter 3) for a description of the removal and
! replacement of the processor assembly.
Factory configurations use processors fitted with passive heat sinks.
Heat Sink
Heat Sink
Retaining Bar
Retaining Clip
(iPAQ 2.0)
Heat Sink
Heat Sink
(iPAQ 2.0)
(iPAQ 1.x)
Processor in
Processor
Flip-Chip Package
Lock/Unlock
Handle
PPGA370
Socket
Figure 210. Processor Assembly and Mounting
WARNING: The iPAQ 1.0/1.2 system board is designed handle a maximum processor
! current load of 18 amps. Installing a replacement processor that draws more than 18 amps
of current may damage the processor and/or the system board.
Compaq iPAQ Series of Desktop Personal Computers 2-15
Second Edition - February 2001
Chapter 2 System Overview
2.4.4 CHIPSET
The chipset is designed to compliment the processor and provide the central point for the system's
data transactions. The Compaq iPAQ 1.0/1.2 system employs the Intel 810E while the iPAQ 2.0
system uses the Intel 815E chipset.
The chipset is composed of a graphics memory controller hub (GMCH), an I/O controller hub
(ICH), and a firmware hub (FWH). Table 2-3 shows a listing of the functions provided by the two
types of chipsets.
Table 2-3. Chipset Functions
Table 2-3.
Chipset Functions
Chipset Component Function
810E 82810E-DC100 Graphics/Memory 2D/3D graphics controller
Controller Hub (GMCH) SDRAM controller supporting 2
PC100 DIMMs
66-/100-/133-MHz FSB
PCI bus I/F
82801AA I/O Controller Hub (ICH) LPC bus I/F
SMBus I/F
IDE I/F with UATA/66 support
AC '97 audio controller
RTC/CMOS
IRQ controller
Power management logic
USB controller (1)
82802 Firmware Controller Hub (FWH) Loaded with Compaq BIOS
Random number generator
815E 82815 Graphics/Memory 2D/3D graphics controller
Controller Hub (GMCH) SDRAM controller supporting 2
PC100 or PC133 DIMMs
66-/100-/133-MHz FSB
PCI bus I/F
82801BA I/O Controller Hub (ICH2) LPC bus I/F
SMBus I/F
IDE I/F with UATA/100 support
AC '97 audio controller
RTC/CMOS
IRQ controller
Power management logic
USB controller (2)
Network interface controller
82802 Firmware Controller Hub (FWH) [1] Loaded with Compaq BIOS
Random number generator
NOTE:
[1] Some units may use a non-Intel equivalent component.
2-16 Compaq iPAQ Series of Desktop Personal Computers
Second Edition February 2001
Technical Reference Guide
2.4.5 SUPPORT COMPONENTS
Input/output functions not provided by the chipset are handled by other support components. Some
of these components also provide "housekeeping" and various other functions as well. Table 2-4
shows the functions provided by the support components.
Table 2-4. Support Component Functions
Table 2-4.
Support Component Functions
Component Name Function Notes
[1]
LPC47B277 or LPC47B357 Keyboard and pointing device I/F
[2]
I/O Controller Diskette I/F
[1]
Serial I/F
[1]
Parallel I/F
AGP, PCI reset generation
ISA serial IRQ converter
Power button logic
Slow speed detection
S3 regulator controller
GPIO ports
AD1881 or AD1885 Audio Codec Audio mixer
Digital-to-analog converter
Analog-to-digital converter
Analog I/O:
Mic input
Line input
CD input
Line output
82559 Ethernet Controller [3] Network interface controller
PHY interface
TUSB2046B USB Hub 4-port USB 1.1-compliant hub
NOTE:
[1] Legacy models only.
[2] Not available for actual use but may be enabled to satisfy OS requirements.
[3] iPAQ 1.0/1.2 systems only.
2.4.6 SYSTEM MEMORY
These systems utilize non-ECC Synchronous DRAM (SDRAM) . Two 168-pin DIMM sockets are
provided and accessible once the right side cover has been removed. IPAQ 1.2 systems use
PC100-type DIMMs and iPAQ 2.0 systems use PC133 DIMMs. Up to 512 megabytes (with
current DIMM technology) maybe installed in each system.
Compaq iPAQ Series of Desktop Personal Computers 2-17
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Chapter 2 System Overview
2.4.7 MASS STORAGE
In a standard configuration the Compaq iPAQ supports two mass storage devices; one internal IDE
hard drive and a removeable-media IDE device (CD-ROM, DVD, or LS-120 Power Drive, etc.)
mounted in the MultiBay. This system uses SMART drives for the internal IDE device. An adapter
is available that allows a secondary IDE hard drive to be installed in the MultiBay. The MultiBay
supports hot-swapping of mass storage devices except for hard drives. The Compaq iPAQ
supports the DriveLock feature for MultiBay hard drives, providing enhanced security for
removeable hard drives.
2.4.8 SERIAL AND PARALLEL INTERFACES
The legacy models include a serial port and a parallel port accessible at the rear of the chassis. The
serial port is RS-232-C/16550-compatible and supports standard baud rates up to 115,200 as well
as two high-speed baud rates of 230K and 460K , and utilize a DB-9 connector. The parallel
interface is Enhanced Parallel Port (EPP1.9) and Enhanced Capability Port (ECP) compatible, and
supports bi-directional data transfers through a DB-25 connector. These interfaces may be disabled
through Setup for enhanced security. The iPAQ 2.0 system uses a snap-on legacy module for
implementing serial and parallel interfaces.
2.4.9 UNIVERSAL SERIAL BUS INTERFACE
All models feature two front panel-accessible Universal Serial Bus (USB) ports that provide a
12Mb/s hot pluggable (Plug 'n Play) interface for peripherals. Legacy-free iPAQ 1.2 models
include three additional USB ports on the rear panel while all iPAQ 2.0 models provide four USB
ports on the rear panel. taccommodate the USB keyboard and mouse supplied with those models.
Units shipped as "legacy-free" include USB keyboards and mice.
2.4.10 GRAPHICS SUBSYSTEM
All models use the graphics controller integrated into the 82810E/DC-100 and 82815 GMCH
component of the chipset. This graphics controller is the equivalent of the Intel i740 controller and
provides up to 1600 x 1200 2D resolution. Pentium III-based systems also include 4 megabytes of
local display cache for increased 3D performance. Celeron-based iPAQ 2.0 systems may be
upgraded with the addition of a 4-MB display cache module.
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Second Edition February 2001
Technical Reference Guide
2.4.11 AUDIO SUBSYSTEM
The audio subsystem features an AC'97 specification-based design and uses the integrated AC97
audio controller of the chipset and an AC'97-compliant audio codec. Microphone and headphone
jacks are accessible on the front panel and line input and output jacks are provided on the rear
panel. A low-distortion 5-watt amplifier drives a long-excursion speaker for optimum sound.
2.5 SPECIFICATIONS
This section includes the environmental, electrical, and physical specifications for the Compaq
iPAQ Series Internet Devices. Where provided, metric statistics are given in parenthesis. All
specifications subject to change without notice.
Table 2-5. Environmental Specifications
Table 2-5.
Environmental Specifications
Parameter Operating Nonoperating
50o to 95o F (10o to 35o C) -24o to 140o F (-30o to 60o C)
Air Temperature
Shock 30.0 g for 2 ms half-sine pulse 60.0 g for 2 ms half-sine pulse
Vibration 0.000215g^ 2/Hz, 10-300 Hz [1] 0.0005g^ 2/Hz, 10-500 Hz [1]
90% Rh @ 28o C max wet bulb [2] 95% Rh @ 38.7o C [2]
Humidity
Maximum Altitude 10,000 ft (3048 m) 30,000 ft (9,144 m)
NOTE:
[1] 0.25 grms nominal
[2] Maximum wet bulb, non-condensing
Table 2-6. Electrical Specifications
Table 2-6.
Electrical Specifications
Parameter U.S. International
Input Line Voltage:
Nominal: 110 - 120 VAC 200 - 240 VAC
Maximum: 90 - 132 VAC 180 - 264 VAC
Input Line Frequency Range:
Nominal: 50 - 60 Hz 50 - 60 Hz
Maximum: 47 - 63 Hz 47 - 63 Hz
Power Supply:
Maximum Continuous Power 90 watts 90 watts
Maximum Line Current Draw 2.5 amps 1.25 amps
Compaq iPAQ Series of Desktop Personal Computers 2-19
Second Edition - February 2001
Chapter 2 System Overview
Table 2-7. Physical Specifications
Table 2-7.
Physical Specifications
IPAQ 1.0/1.2 IPAQ 2.0
Standard Metric Standard Metric
Height 11.80 in 29.97 cm 13.75 in 34.90 cm
W idth 5.66 in 14.38 cm 5.4 in 13.80 cm
Depth 9.44 in 23.98 cm 10.4 in 26.40 cm
W eight 10.7 lb [1] 4.8 kg 10.3 lb [1] 4.68 kg
Table 2-8. MultiBay 24x CD-ROM Drive Specifications
Table 2-8.
MultiBay 24x CD-ROM Drive Specifications
(SP# 161685-B21)
Parameter Measurement
Interface Type / Protocol IDE / ATAPI
Transfer Rate:
Max. Sustained 3.6 MB/s
Burst 16.6 MB/s
Media Type Mode 1,2, Mixed Mode, CD-DA,
Photo CD, Cdi, CD-XA
Capacity:
Mode 1, 12 cm 550 MB
Mode 2, 12 cm 640 MB
8 cm 180 MB
Center Hole Diameter 15 mm
Disc Diameter 8/12 cm
Disc Thickness 1.2 mm
Track Pitch 1.6 um
Laser
53.5 +/- 1.5
Beam Divergence
Output Power 53.6 0.14 mW
Type GaAs
Wave Length 790 +/- 25 nm
Average Access Time:
Random 140 ms
Full Stroke 300 ms
Audio Output Level 0.7 Vrms
Cache Buffer 128 KB
2-20 Compaq iPAQ Series of Desktop Personal Computers
Second Edition February 2001
Technical Reference Guide
Table 2-9. MultiBay 24x CD-ROM Drive Specifications
Table 2-9.
MultiBay 4x DVD-ROM Drive Specifications
(SP# 161685-B21)
Parameter Measurement
Interface Type / Protocol IDE / ATAPI
Transfer Rate:
Max. Sustained (off disk) 5.41 MB/s
Data Bus Burst 16.6 MB/s
Media Types DVD (single/double layer),
DVD-5, DVD-9, DVD-10,
CD-ROM Modes 1 or 2, CD-DA,
Photo CD, Cdi, CD-XA
Capacity:
Mode 1, 12 cm 550 MB
Mode 2, 12 cm 640 MB
8 cm 180 MB
Center Hole Diameter 15 mm
Disc Diameter 8 or 12 cm
Disc Thickness 1.2 mm
Track Pitch 1.6 um
Average Access Time:
DVD:
Random <170 ms
Full Stroke <280 ms
CD:
Random <130 ms
Full stroke <225 ms
Audio Output Level 0.7 Vrms
Cache Buffer 512 KB
Table 2-10. Hard Drive Specifications
Table 2-10.
Hard Drive Specifications
Parameter 4.3 GB 6.0 GB [1] 8.4 GB 10 GB
P/N 158738 161684 158739 N/A
Interface / Protocol IDE / UATA-4 IDE / UATA-4 IDE / UATA-4 IDE / UATA-5
Drive Type 65 65 65 65
Drive Size 3.5/5.25 in 2.5/5.25 in 5.25 in 5.25 in
Interface Transfer Rate (max.) 66.6 MB/s 66.6 MB/s 66.6 MB/s 100 MB/s
Max. Seek Time (w/settling)
2.0 ms 4.0 ms 4.75 ms
Single Track N/A
9.5 ms 12.0 ms 14.9 ms
Average N/A
19.0 ms 23.0 ms 27 ms
Full Stroke (max) N/A
Disk Format (logical):
# of Cylinders 8419 13424 16383 N/A
# of Data Heads 15 15 16 N/A
# of Sectors per Track 63 63 63 N/A
Rotation Speed 5400 RPM 4200 RPM 5400 RPM 5400
Drive Fault Prediction SMART II SMART II SMART III SMART III
NOTE:
[1] For use in MultiBay.
N/A = Not available at press time.
Compaq iPAQ Series of Desktop Personal Computers 2-21
Second Edition - February 2001
Chapter 2 System Overview
This page is intentionally blank.
2-22 Compaq iPAQ Series of Desktop Personal Computers
Second Edition February 2001
Technical Reference Guide
Chapter 3
PROCESSOR/
MEMORY SUBSYSTEM
3. Chapter 3 PROCESSOR/MEMORY SUBSYSTEM
3 .1 INTRODUCTION
This chapter describes the processor/cache memory subsystem of the Compaq iPAQ Desktop
Personal Computer featuring a Celeron or Pentium III processor and the 810E or 815E chipset
(Figure 3-1). The chipset's GMCH supports up to two SDRAM DIMMs and integrates a 2D/3D
graphics controller (covered in Chapter 6).
System Memory
J2
J1
Processor
DIMM
Socket
In
Socket
64-Bit FSB Cntl
FSB I/F
100-MHz
Memory Bus
2D/3D SDRAM
Graphics GMCH Cntlr.
Cntlr.
Hub I/F
May be populated with optional DIMM
Covered in Chapter 6
Covered in Chapter 4
Figure 31. Processor/Memory Subsystem Architecture
This chapter includes the following topics:
Processor [3.2] page 3-2
Memory subsystem [3.3] page 3-5
Subsystem configuration {3.4] page 3-8
3-1
Compaq iPAQ Series of Desktop Personal Computers
Second Edition - February 2001
Chapter 3 Processor/Memory Subsystem
3.2 PROCESSOR
The Compaq iPAQ is configured as either a Celeron-based or Pentium III-based system.
3.2.1 CELERON PROCESSOR
The Celeron processor (Figure 3-2) uses a dual-ALU CPU with branch prediction and MMX
support, floating point unit (FPU) for math coprocessing, a 32-KB primary (L1) cache, and a 128-
KB secondary (L2) cache. All internal functions, except for the front side bus interface (FSB I/F),
operate at processor speed.
Celeron Processor
FPU 32-KB 128-KB
CPU L1 L2
Cache Cache
FSB
I/F
Core processing speed Host bus speed
Figure 32. Celeron Processor Internal Architecture
The Celeron processor is software-compatible with earlier generation Pentium II, Pentium MMX,
Pentium, and x86 processors. The MMX support provided by the Celeron consists of 57 special
instructions for accelerating multimedia communications applications. Such applications often
involve computing-intensive loops that can take up as much as 90 percent of the CPU's execution
time. Using a parallel-processing technique called single-instruction multiple-data (SIMD), MMX
logic processes data 64 bits at a time. Specific applications that can benefit from MMX technology
include 2D/3D graphics, audio, speech recognition, video codecs, and data compression.
The 82810-DC100 GMCH supports the processors listed in the following table:
Table 31. Celeron Processor Statistical Comparison
Table 3-1.
Celeron Processor Statistical Comparison
Core/L1/L2 FSB Core
Processor Freq. Freq. Voltage Notes
Celeron 500 500 MHz 66 MHz 2.00 V [1]
Celeron 533 533 MHz 66 MHz 2.00 V
Celeron 700 700 MHz 66 MHz 1.65 V [2]
NOTES:
[1] Standard processor for iPAQ 1.0 systems.
[2] Standard processor for iPAQ 2.0 systems
3-2 Compaq iPAQ Series of Desktop Personal Computers
Second Edition - February 2001
Technical Reference Guide
3.2.2 PENTIUM III PROCESSOR
The Pentium III processor's architecture (Figure 3-3) includes the same core functionality as
described previously for the Celeron processor but includes a larger L2 cache and higher
processing speeds.
Pentium III Processor
FPU 32-KB 256-KB
CPU L1 L2
Cache or
Cache
FSB
I/F
Host bus speed
Full processing speed
Figure 33. Pentium III Processor Internal Architecture
These systems support the processor types listed in the following table.
Table 32. Pentium III Processor Statistical Comparison
Table 3-2.
Pentium III Processor Statistical Comparison
CPU/L1 L2 FSB
Processor Speed Size / Speed Speed Notes
Pentium III 500E 500 MHz 256 KB @ 500 MHz 100 MHz [1]
Pentium III 533EB 533 MHz 256 KB @ 533 MHz 133 MHz
Pentium III 550E 550 MHz 256 KB @ 550 MHz 100 MHz
Pentium III 600E 600 MHz 256 KB @ 600 MHz 100 MHz
Pentium III 600EB 600 MHz 256 KB @ 600 MHz 133 MHz
Pentium III 667 667 MHz 256 KB @ 667 MHz 133 MHz
Pentium III 700 700 MHz 256 KB @ 700 MHz 100 MHz
Pentium III 733 733 MHz 256 KB @ 733 MHz 133 MHz [2]
Pentium III 866 866 MHz 256 KB @ 866 MHz 133 MHz [3]
NOTES:
[1] Standard processor on iPAQ 1.0 systems.
[2] Standard processor on iPAQ 1.2 systems.
[3] Standard processor on iPAQ 2.0 systems.
The Pentium III processor is software-compatible with Celeron, Pentium II, Pentium MMX,
Pentium, and x86 processors and also features 70 FPU-based streaming SIMD extensions (SSE)
that, when implemented by appropriate software, can enhance 3D transforming and speech
processing operations. Operating system requirements for SSE support are as follows:
Operating SystemLevel of SSE Support
Windows 95 No SSE support
Windows 98, OSR0 SSE support though ISV and OpenGL 6.1 applications only
Windows 98, OSR1 SSE support though ISV, OpenGL, and DirectX applications
Windows 2000 SSE support with ISV, OpenGL, and DirectX applications
Windows NT 4.0 SSE support requires driver and Service Pack 4 (SP5 recommended)
3-3
Compaq iPAQ Series of Desktop Personal Computers
Second Edition - February 2001
Chapter 3 Processor/Memory Subsystem
3.2.3 PROCESSOR UPGRADING
All units use the PGA370 ZIF mounting socket and ship with either a Celeron or Pentium III
processor installed. To replace the processor, use the following procedure:
1. Power down the system and disconnect the power cord.
2. Remove the right outer (carbon) panel.
3. On iPAQ 1.x systems, disconnect and remove the hard drive.
4. Remove the right chassis access panel.
5. After insuring that you have been properly grounded, remove the heatsink retaining clip (on
the iPAQ 1.x by prying) or retaining bar (on the iPAQ 2.0 by lifting up the lock handle and
then pressing the two ends together).
6. Remove the heatsink by twisting slightly before lifting off.
7. Lift the release arm of the PGA370 socket to the upright position.
8. Lift the processor package from the socket.
Replacement of the new processor is a reversal of steps 1-8.
CAUTION: These systems are designed for using processors with passive heat sinks.
! Installing a processor with an integrated fan on an iPAQ 1.x system is possible but not
recommended (see Warning below). Do not install a processor with an integrated fan
in an iPAQ 2.0 unit.
When replacing the processor it is recommended that the replacement processor be of the same
family as the existing processor (i.e., Celeron for Celeron, or Pentium for Pentium).
WARNING: Upgrading iPAQ 1.0/1.2 models to a faster processor is possible provided
! that the new processor does not draw more than 18 amps of current. Using a processor
that draws in excess of 18 amps may create a thermal condition and damage the system
board. IPAQ 2.0 models may be upgraded to processors of up to but not exceeding 1
GHz. Installing a processor faster than 1 GHz in an iPAQ 2.0 unit may cause damage to
the processor and/or the system board.
The processor core voltage and operating frequency are automatically set early in the power cycle
process. No DIP switch settings are involved in replacing the processor.
3-4 Compaq iPAQ Series of Desktop Personal Computers
Second Edition - February 2001
Technical Reference Guide
3 .3 MEMORY SUBSYSTEM
The iPAQ 1.0/1.2 system supports PC100 SDRAM for system memory. The iPAQ 2.0 system
supports PC133 SDRAM DIMMs. These systems provide two 168-pin SDRAM DIMM sockets
that accommodate single- or double-sided DIMMs. DIMMs should always be installed starting
with the socket closest to the GMCH and/or processor These systems are designed for using
non-ECC DIMMs only.
If using memory modules from third party suppliers the following DIMM type is recommended:
For iPAQ 1.0/1.2 models: 100-MHz (PC100) unbuffered non-ECC RAM supporting CAS
latency (CL) 2 or 3 with a data access time (clock-to-data out) of 9.0 ns or less @ CL=2 or
CL=3.
The 82810E GMCH supports 16-, 64-, and 128-Mb technology DIMMs for a maximum of 256
megabytes of memory space (with two 128-MB DIMMs).
NOTE: The 82810e GMCH performs memory accesses at 100 MHz regardless of
the FSB frequency.
For iPAQ 2.0 models: 133-MHz (PC133) unbuffered non-ECC RAM supporting CAS latency
(CL) 2 or 3 with a data access time (clock-to-data out) of 9.0 ns or less @ CL=2 or CL=3.
PC100 DIMMs may be used with a slight reduction in performance.
The 82815 GMCH supports 16-, 64-, 128-, and 256-Mb technology DIMMs for a maximum of
512 megabytes of memory space (with two 256-MB DIMMs).
The RAM type and operating parameters are detected during POST by the system BIOS using the
serial presence detect (SPD) method. This method employs an I2C bus to communicate with an
EEPROM on each installed DIMM. The EEPROM holds the type and operating parameter data.
The supported format complies with the JEDEC specification for 128-byte EEPROMs. This
system also provides support for 256-byte EEPROMs to include additional Compaq-added
features such as part number and serial number. The SPD format as supported in this system is
shown in Table 3-3.
The key SPD bytes that BIOS checks for compatibility are 2, 9, 10, 18, 23, and 24. If BIOS
detects EDO DIMMs a "memory incompatible" message will be displayed and the system
will halt. Once BIOS determines the DIMM type the DRAM speed and CAS latency is checked
based on the following criteria:
Access
from
Bus Speed Cycle Time Clock
100/133 MHz 10 ns 6 ns @ 50 pf loading
Only CAS latencies of 2 or 3 are supported. If DIMMs with unequal CAS latencies are installed
then operation will occur based on the DIMM with the greatest latency.
On iPAQ 2.0 systems, if the BIOS detects an incompatible DIMM the NUM LOCK will blink for
a short period of time during POST and an error message may or may not be displayed before the
system hangs.
3-5
Compaq iPAQ Series of Desktop Personal Computers
Second Edition - February 2001
Chapter 3 Processor/Memory Subsystem
The SPD address map is shown below.
Table 33. SPD Address Map (SDRAM DIMM)
Table 3-3.
SPD Address Map (SDRAM DIMM)
Byte Description Notes Byte Description Notes
0 No. of Bytes Written Into EEPROM [1] 27 Min. Row Prechge. Time [7]
1 Total Bytes (#) In EEPROM [2] 28 Min. Row Active to [7]
Delay
2 Memory Type 29 Min. RAS to CAS Delay [7]
3 No. of Row Addresses On DIMM [3] 30, 31 Reserved
4 No. of Column Addresses On DIMM 32..61 Superset Data [7]
5 No. of Module Banks On DIMM 62 SPD Revision [7]
6, 7 Data Width of Module 63 Checksum Bytes 0-62
8 Voltage Interface Standard of DIMM 64-71 JEP-106E ID Code [8]
9 Cycletime @ Max CAS Latency (CL) [4] 72 DIMM OEM Location [8]
10 Access From Clock [4] 73-90 OEM's Part Number [8]
11 Config. Type (Parity, Nonparity, etc.) 91, 92 OEM's Rev. Code [8]
12 Refresh Rate/Type [4] [5] 93, 94 Manufacture Date [8]
13 W idth, Primary DRAM 95-98 OEM's Assembly S/N [8]
14 Error Checking Data Width 99-125 OEM Specific Data [8]
15 Min. Clock Delay [6] 126, 127 Reserved
16 Burst Lengths Supported 128-131 Compaq header "CPQ1" [9]
17 No. of Banks For Each Mem. Device [4] 132 Header checksum [9]
18 CAS Latencies Supported [4] 133-145 Unit serial number [9] [10]
19 CS# Latency [4] 146 DIMM ID [9] [11]
20 W rite Latency [4] 147 Checksum [9]
21 DIMM Attributes 148-255 Reserved [9]
22 Memory Device Attributes
23 Min. CLK Cycle Time at CL X-1 [7]
24 Max. Acc. Time From CLK @ CL X-1 [7]
25 Min. CLK Cycle Time at CL X-2 [7]
26 Max. Acc. Time From CLK @ CL X-2 [7]
NOTES:
[1] Programmed as 128 bytes by the DIMM OEM
[2] Must be programmed to 256 bytes.
[3] High order bit defines redundant addressing: if set (1), highest order RAS# address must be
re-sent as highest order CAS# address.
[4] Refer to memory manufacturer's datasheet
[5] MSb is Self Refresh flag. If set (1), assembly supports self refresh.
[6] Back-to-back random column addresses.
[7] Field format proposed to JEDEC but not defined as standard at publication time.
[8] Field specified as optional by JEDEC but required by this system.
[9] Compaq usage. This system requires that the DIMM EEPROM have this
space available for reads/writes.
[10] Serial # in ASCII format (MSB is 133). Intended as backup identifier in case vender data is
invalid. Can also be used to indicate s/n mismatch and flag system administrator of possible
system tampering.
[11] Contains the socket # of the module (first module is "1"). Intended as backup identifier (refer to
note [10]).
3-6 Compaq iPAQ Series of Desktop Personal Computers
Second Edition - February 2001
Technical Reference Guide
Figure 3-4 shows the system memory map.
4 GB
FFFF FFFFh High BIOS Area
(2 MB)
FFE0 0000h
FFDF FFFFh
PCI Memory
(18 MB)
FEC1 0000h
FEC0 FFFFh APIC Config. Space
(64 KB)
FEC0 0000h
FEBF FFFFh
PCI Memory
Host,
Expansion
PCI, AGP Area
(2548 MB)
4000 0000h 1 GB
3FFF FFFFh
Host/PCI Memory
Expansion
(1008 MB)
0100 0000h
16 MB
00FF FFFFh
Host, PCI,
Extended Memory
ISA Area
(15 MB)
0010 0000h
1 MB
000F FFFFh System BIOS Area
(64 KB)
000F 0000h
000E FFFFh Extended BIOS
Area
000E 0000h
000D FFFFh (64 KB)
Option ROM
(128 KB)
000C 0000h
000B FFFFh
Graphics/SMRAM
DOS Compatibility
RAM (128 KB)
Area
000A 0000h
640 KB
0009 FFFFh
Fixed Mem. Area
(128 KB)
0008 0000h 512 KB
0007 FFFFh
Base Memory
(512 KB)
0000 0000h
NOTE: All locations in memory are cacheable. Base memory is always mapped to DRAM. The next 128 KB
fixed memory area can, through the north bridge, be mapped to DRAM or to PCI space. Graphics RAM area is
mapped to PCI or AGP locations.
Figure 34. System Memory Map
3-7
Compaq iPAQ Series of Desktop Personal Computers
Second Edition - February 2001
Chapter 3 Processor/Memory Subsystem
3 .4 SUBSYSTEM CONFIGURATION
The GMCH component provides the configuration function for the processor/memory subsystem.
Table 3-4 lists the configuration registers used for setting and checking such parameters as
memory control and PCI bus operation. These registers reside in the PCI Configuration Space and
accessed using the methods described in Chapter 4, section 4.2.
Table 34. Host/PCI Bridge Configuration Registers (GMCH, Function 0)
Table 3-4.
Host/PCI Bridge Configuration Registers (GMCH, Function 0)
PCI Conf. Reset PCI Conf. Reset
Addr. Register Value Addr. Register Value
00, 01h Vender ID 8086h 6A, 6Bh DRAM Control Reg. 00h
02, 03h Device ID [1] 6C..6Fh Memory Buffer Strength 55h
04, 05h Command 0006h 70h Multi-Transaction Timer 00h
06, 07h Status 0210h 71h CPU Latency Timer 10h
08h Revision ID -- 72h SMRAM Control 02h
09..0Bh Class Code -- 90h Error Command 00h
0Dh Latency Timer 00h 91h Error Status Register 0 00h
0Eh Header Type 00h 92h Error Status Register 1 00h
10..13h Aperture Base Config. 8 93h Reset Control 00h
50, 51h PAC Config. Reg. 00h A0..A3h AGP Capability Identifier N/A
53h Data Buffer Control 83h A4..A7h AGP Status N/A
55..56h DRAM Row Type 00h A8..ABh AGP Command 00h
57h DRAM Control 01h B0..B3h AGP Control 00h
58h DRAM Timing 00h B4h Aperture Size 0000h
59..5Fh PAM 0..6 Registers 00h B8..BBh Aperture Translation Table 0000h
60..67h DRAM Row Boundary 01h BCh Aperture I/F Timer 00h
68h Fixed DRAM Hole 00h BDh Low Priority Timer 00h
NOTES:
Refer to Intel Inc. documentation for detailed description of registers.
Assume unmarked locations/gaps as reserved.
[1] 2500 = iPAQ 1.x, 1130 = iPAQ 2.0
3-8 Compaq iPAQ Series of Desktop Personal Computers
Second Edition - February 2001
Technical Reference Guide
Chapter 4
SYSTEM SUPPORT
4. Chapter 4 SYSTEM SUPPORT
4 .1 INTRODUCTION
This chapter covers subjects dealing with basic system architecture and covers the following
topics:
PCI bus overview (4.2) page 4-2
System resources (4.3) page 4-7
System clock distribution (4.4) page 4-11
Real-time clock and configuration memory (4.5) page 4-11
System management (4.6) page 4-22
Register map and miscellaneous functions (4.7) page 4-26
This chapter covers functions provided by off-the-shelf chipsets and therefore describes only basic
aspects of these functions as well as information unique to the sytems covered in this guide. For
detailed information on specific components, refer to the applicable manufacturer's
documentation.
4-1
Compaq iPAQ Series of Desktop Personal Computers
Second Edition - February 2001
Chapter 4 System Support
4.2 PCI BUS OVERVIEW
NOTE: This section describes the PCI bus in general and highlights bus implementation
in this particular system. For detailed information regarding PCI bus operation, refer to
the PCI Local Bus Specification Revision 2.2.
These systems implement a 32-bit Peripheral Component Interconnect (PCI) bus (spec. 2.2)
operating at 33 MHz. The PCI bus handles address/data transfers through the identification of
devices and functions on the bus. A device is typically defined as a component or slot that resides
on the PCI bus (although some components such as the GMCH and ICH are organized as multiple
devices). A function is defined as the end source or target of the bus transaction. A device may
contain one or more functions.
In the standard configuration these systems use a hierarchy of three PCI buses (Figure 4-1). The
PCI bus #0 is internal to the GMCH/ICH chipset components and is not physically accessible. The
AGP bus that services the AGP slot is designated as PCI bus #1. As this system is designed for
simplicity of system management, the PCI buses are not available for expansion purposes.
82810E or 82815 GMCH Component
Mem. Cntlr. PCI
Function Direct AGP
Bus #0
Graphics
Controller
Hub Link I/F
Hub Link Bus
82801 ICH or ICH2 Component
Hub Link I/F
PCI Bus #0
PCI Bridge
NIC EIDE USB SMBus LPC AC97
Function
I/F Controller I/F Controller Bridge Audio
Function Function Function Function Function Function
PCI
Bus #2
82559
Network
I/F Cntlr.
iPAQ 2.0 (ICH2) only.
iPAQ 1.0/1.2 (ICH) only.
Figure 4-1. PCI Bus Devices and Functions
4-2 Compaq iPAQ Series of Desktop Personal Computers
Second Edition February 2001
Technical Reference Guide
4.2.1 PCI BUS TRANSACTIONS
The PCI bus consists of a 32-bit path (AD31-00 lines) that uses a multiplexed scheme for handling
both address and data transfers. A bus transaction consists of an address cycle and one or more
data cycles, with each cycle requiring a clock (PCICLK) cycle. High performance is realized
during burst modes in which a transaction with contiguous memory locations requires that only one
address cycle be conducted and subsequent data cycles are completed using auto-incremented
addressing. Four types of address cycles can take place on the PCI bus; I/O, memory,
configuration, and special. Address decoding is distributed (left up to each device on the PCI bus).
4.2.1.1 I/O and Memory Cycles
For I/O and memory cycles, a standard 32-bit address decode (AD31..0) for byte-level addressing
is handled by the appropriate PCI device. For memory addressing, PCI devices decode the
AD31..2 lines for dword-level addressing and check the AD1,0 lines for burst (linear-
incrementing) mode. In burst mode, subsequent data phases are conducted a dword at a time with
addressing assumed to increment accordingly (four bytes at a time).
| 161685-B21
7M-0300B-WW
|
