Digital Equipment 5300 User manual

DIGITALServer5300
ServiceGuide
Part Number: ER−K8FWW−SG. A01
February 1998
This manual is for anyone who services the DIGITAL Server 5300 systems. It
includes troubleshooting information, configuration rules, and instructions for removal
and replacement of field-replaceable units.
Digital Equipment Corporation
Maynard, Massachusetts

February 1998
Digital Equipment Corporation makes no representations that the use of its products in the manner described in this
publication will not infringe on existing or future patent rights, nor do the descriptions contained in this publication
imply the granting of licenses to make, use, or sell equipment or software in accordance with the description.
Possession, use, or copying of the software described in this publication is authorized only pursuant to a valid
written license from DIGITAL or an authorized sublicensor.
© Digital Equipment Corporation 1998. All rights reserved.
The following are trademarks of Digital Equipment Corporation: Alpha, DIGITAL, RRD46, StorageWorks, and
the DIGITAL logo.
The following are third-party trademarks:
Adobe and PostScript are registered trademarks of Adobe Systems, Incorporated.
Helvetica and Times are registered trademarks of Linotype Co.
Microsoft and MS-DOS are registered trademarks and Windows is a trademark of Microsoft Corporation.

iii
Table of Contents
1 System Overview
System Enclosure....................................................................................................................1–2
Cover Interlock................................................................................................................1–3
Operator Control Panel and Drives..........................................................................................1–4
System Consoles.....................................................................................................................1–6
AlphaBIOS Boot Menu....................................................................................................1–6
SRM Console...................................................................................................................1–6
AlphaBIOS Console.........................................................................................................1–7
Environment Variables.....................................................................................................1–7
System Architecture................................................................................................................1–8
CPU Types ........................................................................................................................... 1–10
Alpha Chip Composition................................................................................................ 1–11
CPU Configuration Rules............................................................................................... 1–11
Memory................................................................................................................................ 1–12
Memory Variants...........................................................................................................1–13
Memory Operation.........................................................................................................1–13
Memory Configuration Rules......................................................................................... 1–13
Memory Addressing.............................................................................................................. 1–14
System Motherboard.............................................................................................................1–16
System Bus (Backplane) ................................................................................................ 1–18
System Bus to PCI Bus Bridge....................................................................................... 1–20
PCI I/O Subsystem.........................................................................................................1–22
Remote Control Logic.................................................................................................... 1–24
Power Control Logic......................................................................................................1–26
Power Circuit and Cover Interlock........................................................................................ 1–28
Power Supply........................................................................................................................1–30
Description .................................................................................................................... 1–31
Power Supply Features................................................................................................... 1–31

iv
Power Up/Down Sequence.................................................................................................... 1–32
Maintenance Bus (I2C Bus)................................................................................................... 1–34
Monitor.......................................................................................................................... 1–35
Fault Display ................................................................................................................. 1–35
Error State ..................................................................................................................... 1–35
Configuration Tracking.................................................................................................. 1–35
StorageWorks Drives............................................................................................................ 1–36
2 Power-Up
Control Panel.......................................................................................................................... 2–2
Power-Up Sequence................................................................................................................ 2–4
Definitions....................................................................................................................... 2–4
SROM Power-Up Test Flow................................................................................................... 2–8
SROM Errors Reported......................................................................................................... 2–11
XSROM Power-Up Test Flow .............................................................................................. 2–12
XSROM Errors Reported...................................................................................................... 2–15
Console Power-Up Tests....................................................................................................... 2–16
Console Device Determination ............................................................................................. 2–18
Console Device Options................................................................................................. 2–19
Console Power-Up Display................................................................................................... 2–20
Fail-Safe Loader................................................................................................................... 2–24
3 Troubleshooting
Troubleshooting with LEDs.................................................................................................... 3–2
System Motherboard LEDs.............................................................................................. 3–3
Troubleshooting Power Problems ........................................................................................... 3–4
Power Problem List ......................................................................................................... 3–4
Halt Caused by Power, Fan, or Overtemperature Condition ............................................. 3–5
If Power Problem Occurs at Power-Up............................................................................. 3–5
Recommended Order for Troubleshooting Failure at Power-Up....................................... 3–5
Running Diagnostics — Test Command................................................................................. 3–6
Releasing Secure Mode ..........................................................................................................3–7
Testing an Entire System........................................................................................................ 3–8
Testing Memory................................................................................................................... 3–10
Testing PCI.................................................................................................................... 3–12
Other Useful Console Commands......................................................................................... 3–14
4 Error Registers
External Interface Status Register - EI_STAT......................................................................... 4–2

v
External Interface Address Register - EI_ADDR.....................................................................4–5
MC Error Information Register 0 (MC_ERR0 - Offset = 800)................................................. 4–6
MC Error Information Register 1 (MC_ERR1 - Offset = 840)................................................. 4–7
CAP Error Register (CAP_ERR - Offset = 880)......................................................................4–9
PCI Error Status Register 1 (PCI_ERR1 - Offset = 1040)...................................................... 4–11
5 Removal and Replacement
System Safety.........................................................................................................................5–1
FRU List.................................................................................................................................5–2
System Exposure ....................................................................................................................5–6
Exposing the System........................................................................................................5–7
Dressing the System.........................................................................................................5–7
CPU Removal and Replacement.............................................................................................5–8
Removal .......................................................................................................................... 5–9
Replacement.................................................................................................................... 5–9
Verification......................................................................................................................5–9
CPU Fan Removal and Replacement .................................................................................... 5–10
Removal ........................................................................................................................5–11
Replacement.................................................................................................................. 5–11
Verification.................................................................................................................... 5–11
Memory Riser Card Removal and Replacement.................................................................... 5–12
Removal ........................................................................................................................5–13
Replacement.................................................................................................................. 5–13
Verification.................................................................................................................... 5–13
DIMM Removal and Replacement........................................................................................ 5–14
Removal ........................................................................................................................5–15
Replacement.................................................................................................................. 5–15
Verification.................................................................................................................... 5–15
System Motherboard Removal and Replacement.................................................................. 5–16
Removal ........................................................................................................................5–17
Replacement.................................................................................................................. 5–17
Verification.................................................................................................................... 5–17
PCI/EISA Option Removal and Replacement ....................................................................... 5–18
Removal ........................................................................................................................5–19
Replacement.................................................................................................................. 5–19
Verification.................................................................................................................... 5–19
Power Supply Removal and Replacement............................................................................. 5–20
Removal ........................................................................................................................5–21
Replacement.................................................................................................................. 5–21
Verification.................................................................................................................... 5–21
Power Harness Removal and Replacement............................................................................ 5–22

vi
Removal ........................................................................................................................ 5–23
Replacement.................................................................................................................. 5–23
Verification.................................................................................................................... 5–23
System Fan Removal and Replacement ................................................................................ 5–24
Removal ........................................................................................................................ 5–25
Replacement.................................................................................................................. 5–25
Verification.................................................................................................................... 5–25
Cover Interlock Removal and Replacement.......................................................................... 5–26
Removal ........................................................................................................................ 5–27
Replacement.................................................................................................................. 5–27
Verification.................................................................................................................... 5–27
Operator Control Panel Removal and Replacement ............................................................. 5–28
Removal ........................................................................................................................ 5–29
Replacement.................................................................................................................. 5–29
Verification.................................................................................................................... 5–29
CD-ROM Removal and Replacement................................................................................... 5–30
Removal ........................................................................................................................ 5–31
Replacement.................................................................................................................. 5–31
Verification.................................................................................................................... 5–31
Floppy Removal and Replacement........................................................................................ 5–32
Removal ........................................................................................................................ 5–33
Replacement.................................................................................................................. 5–33
Verification.................................................................................................................... 5–33
SCSI Disk Removal and Replacement.................................................................................. 5–34
Removal ........................................................................................................................ 5–35
Replacement.................................................................................................................. 5–35
Verification.................................................................................................................... 5–35
StorageWorks Backplane Removal and Replacement........................................................... 5–36
Removal ........................................................................................................................ 5–37
Replacement.................................................................................................................. 5–37
Verification.................................................................................................................... 5–37
StorageWorks Ultra SCSI Bus Extender Removal and Replacement..................................... 5–38
Removal ........................................................................................................................ 5–39
Replacement.................................................................................................................. 5–39
Verification.................................................................................................................... 5–39
6 Running Utilities
Running Utilities from a Graphics Monitor............................................................................. 6–2
Running Utilities from a Serial Terminal................................................................................ 6–3
Running ECU......................................................................................................................... 6–4
Running RAID Standalone Configuration Utility.................................................................... 6–5

vii
Updating Firmware with LFU.................................................................................................6–6
Updating Firmware from the CD-ROM............................................................................6–8
Updating Firmware from a Network Device................................................................... 6–12
LFU Commands............................................................................................................. 6–16
Updating Firmware from AlphaBIOS.................................................................................... 6–19
Upgrading AlphaBIOS.......................................................................................................... 6–20
7 Halts, Console Commands, and Environment Variables
Halt Button Functions.............................................................................................................7–2
Using the Halt Button.............................................................................................................7–2
Using Halt to Clear the Console Password .......................................................................7–2
Halt Assertion.........................................................................................................................7–3
Summary of SRM Console Commands...................................................................................7–5
Summary of SRM Environment Variables .......................................................................7–7
Recording Environment Variables ..........................................................................................7–8
8 Managing the System Remotely
RCM Overview.......................................................................................................................8–2
First-Time Setup.....................................................................................................................8–3
Configuring the Modem...................................................................................................8–4
Qualified Modems.....................................................................................................8–4
Modem Configuration Procedure...............................................................................8–4
Dialing In and Invoking RCM..........................................................................................8–5
Dialing In and Invoking RCM...................................................................................8–5
Using RCM Locally.........................................................................................................8–6
RCM Commands....................................................................................................................8–7
Command Conventions.............................................................................................8–8
Dial-Out Alerts..................................................................................................................... 8–16
Enabling Dial-Out Alerts ............................................................................................... 8–16
Composing the Dial-Out String...................................................................................... 8–17
Using the RCM Switchpack.................................................................................................. 8–19
Uses of the Switchpack.................................................................................................. 8–21
Changing a Switch Setting............................................................................................. 8–21
Resetting the RCM to Factory Defaults.......................................................................... 8–22
Troubleshooting Guide ......................................................................................................... 8–23
Modem Dialog Details.......................................................................................................... 8–26
Default Initialization and Answer Strings....................................................................... 8–26
Modifying Initialization and Answer Strings.................................................................. 8–26
Initialization String Substitutions...................................................................................8–27

viii
Figures
Figure 1-1 System Enclosure................................................................................ 1–2
Figure 1-2 Cover Interlock Circuit........................................................................ 1–3
Figure 1-3 Control Panel Assembly ...................................................................... 1–4
Figure 1-4 AlphaBIOS Boot Menu........................................................................ 1−6
Figure 1-5 Architecture Diagram.......................................................................... 1–8
Figure 1-6 CPU Module Placement......................................................................1–10
Figure 1-7 Memory Placement.............................................................................1–12
Figure 1-8 How Memory Addressing Is Calculated..............................................1–14
Figure 1-9 System Motherboard...........................................................................1–16
Figure 1-10 System Bus Block Diagram..............................................................1–18
Figure 1-11 System Bus to PCI Bus Bridge Block Diagram.................................1–20
Figure 1-12 PCI Block Diagram ..........................................................................1–22
Figure 1-13 Remote Control Logic ......................................................................1–24
Figure 1-14 Power Control Logic.........................................................................1–26
Figure 1-15 Power Circuit Diagram.....................................................................1–28
Figure 1-16 Back of Power Supply and Location.................................................1–30
Figure 1-17 Power Up/Down Sequence Flowchart...............................................1–32
Figure 1-18 I2C Bus Block Diagram.....................................................................1–34
Figure 1-19 StorageWorks Drive Location...........................................................1–36
Figure 2-1 Control Panel and LCD Display........................................................... 2–2
Figure 2-2 Power-Up Flow ................................................................................... 2–4
Figure 2-3 Contents of FEPROMs ........................................................................ 2–5
Figure 2-4 Console Code Critical Path (Block Diagram)....................................... 2–6
Figure 2-5 SROM Power-Up Test Flow................................................................ 2–8
Figure 2-6 XSROM Power-Up Flowchart ............................................................2–12
Figure 2-7 Console Device Determination Flowchart...........................................2–18
Figure 3-1 System Motherboard LEDs.................................................................. 3–2
Figure 5-1 System FRU Locations........................................................................ 5–2
Figure 5-2 Exposing the System ........................................................................... 5–6
Figure 5-3 Removing CPU Module....................................................................... 5–8
Figure 5-4 Removing CPU Fan............................................................................5–10
Figure 5-5 Removing Memory Riser Card...........................................................5–12
Figure 5-6 Removing a DIMM from a Memory Riser Card..................................5–14
Figure 5-7 Removing System Motherboard..........................................................5–16
Figure 5-8 Removing PCI/EISA Option...............................................................5–18
Figure 5-9 Removing Power Supply ....................................................................5–20
Figure 5-10 Removing Power Harness................................................................ 5−22
Figure 5-11 Removing System Fan..................................................................... 5−24
Figure 5-12 Removing Cover Interlock............................................................... 5−26
Figure 5-13 Removing the OCP.......................................................................... 5−28
Figure 5-14 Removing CD-ROM........................................................................ 5−30

ix
Figure 5-15 Removing Floppy ............................................................................5−32
Figure 5-16 Removing StorageWorks Disk.........................................................5−34
Figure 5-17 Removing StorageWorks Backplane................................................ 5−36
Figure 5-18 Removing StorageWorks Ultra SCSI Bus Extender..........................5−38
Figure 6-1 Running a Utility from a Graphics Monitor.......................................... 6–2
Figure 6-2 Starting LFU from the AlphaBIOS Console......................................... 6–6
Figure 6-3 AlphaBIOS Setup Screen...................................................................6−19
Figure 8-1 RCM Connections ............................................................................... 8–3
Figure 8-2 Location of RCM Switchpack on System Board ................................ 8–19
Figure 8-3 RCM Switches (Factory Settings)...................................................... 8–20
Tables
Table 1-1 Chip Description................................................................................. 1–11
Table 1-2 CPU Variants...................................................................................... 1–11
Table 1-3 Memory Variants................................................................................ 1–13
Table 1-4 PCI Motherboard Slot Numbering....................................................... 1–22
Table 1-5 Remote Control Switch Functions....................................................... 1–25
Table 2-1 Control Panel Display...........................................................................2−3
Table 2-2 SROM Tests ....................................................................................... 2–10
Table 2-3 XSROM Tests..................................................................................... 2–13
Table 2-4 Memory Tests..................................................................................... 2–14
Table 2-5 IOD Tests ........................................................................................... 2–16
Table 2-6 PCI Motherboard Tests ....................................................................... 2−17
Table 4-1 External Interface Status Register ......................................................... 4–4
Table 4-2 Loading and Locking Rules for External Interface Registers................. 4–5
Table 4-3 MC Error Information Register 0.......................................................... 4–6
Table 4-4 MC Error Information Register............................................................. 4–8
Table 4-5 CAP Error Register............................................................................... 4–9
Table 4-6 PCI Error Status Register.................................................................... 4–11
Table 5-1 Field-Replaceable Unit Part Numbers................................................... 5–2
Table 6-1 AlphaBIOS Option Key Mapping .........................................................6−3
Table 6-2 LFU Command Summary...................................................................6−16
Table 7-1 Results of Pressing the Halt Button.......................................................7−2
Table 7-2 Summary of SRM Console Commands.................................................7−5
Table 7-3 Environment Variable Summary...........................................................7−7
Table 7-4 Environment Variables Worksheet........................................................7−8
Table 8-1 RCM Command Summary.................................................................... 8–7
Table 8-2 RCM Status Command Fields............................................................. 8–15
Table 8-3 Elements of the Dial-Out String.......................................................... 8–18
Table 8-4 RCM Switch Settings.......................................................................... 8−20
Table 8-5 RCM Troubleshooting ........................................................................8−23

xi
Preface
Intended Audience
This manual is written for the customer service engineer.
Document Structure
This manual uses a structured documentation design. Topics are organized into small
sections for efficient reference. Each topic begins with an abstract, followed by an
illustration or example, and ends with descriptive text. This manual has eight chapters, as
follows:
Chapter 1, System Overview, introduces the DIGITAL Server 5300 system. It
describes each system component.
Chapter 2, Power-Up, provides information on how to interpret the power-up display
on the operator control panel, the console screen, and system LEDs. It also
describes how hardware diagnostics execute when the system is initialized.
Chapter 3, Troubleshooting, describes troubleshooting during power-up and booting,
as well as the test command.
Chapter 4, Error Registers, describes the error registers used to hold error
information.
Chapter 5, Removal and Replacement, describes removal and replacement
procedures for field-replaceable units (FRUs).
Chapter 6, Running Utilities, explains how to run utilities such as the EISA
Configuration Utility and RAID Standalone Configuration Utility.
Chapter 7, Halts, Console Commands, and Environment Variables, summarizes the
commands used to examine and alter the system configuration.
Chapter 8, Managing the System Remotely, describes how to use the Remote
Console Manager (RCM) to monitor and control the system remotely.

xii
Documentation Titles
The following table lists other books in the documentation set.
System Documentation
Title Order Number
User and Installation Documentation Kit
DIGITAL Server 5300 User’s Guide
DIGITAL Server 5300 Basic Installation
QC–06CAB–H8
ER−K8FWW−UA
ER–K8FWW–IM
Information on the Internet
Access the latest system firmware with a Web browser as follows:
http://www.windowsnt.digital.com/

DIGITAL Server 5300 1–1
1
System Overview
The DIGITAL Server 5300 system base unit consists of up to two CPUs, up to 2 Gbytes of
memory, 6 I/O slots, and up to 7 SCSI storage devices. The system is enclosed in a
pedestal. DIGITAL Server 5300 systems can also be mounted in a standard 19” rack.
The DIGITAL Server 5300 system supports the Windows NT operating system.
Topics in this chapter include the following:
• System Enclosure
• Operator Control Panel and Drives
• System Consoles
• System Architecture
• CPU Types
• Memory
• Memory Addressing
• System Motherboard
• System Bus Backplane
• System Bus to PCI Bus Bridge
• PCI I/O Subsystem
• Remote Control Logic
• Power Control Logic
• Power Circuit and Cover Interlock
• Power Supply
• Power Up/Down Sequence
• Maintenance Bus (I2C Bus)
• StorageWorks Drives

System Overview
1–2 DIGITAL Server 5300
System Enclosure
The system has up to two CPU modules and up to 2 Gbytes of memory. A
single fast wide or fast wide Ultra SCSI StorageWorks shelf provides
storage.
Figure 1-1 System Enclosure
PKW-0500-97
1
2
3
4
6
5
The numbered callouts in Figure 1-1 refer to the system components.
 System card cage, which holds the system motherboard and the CPU, memory, and
system I/O.
 PCI/EISA section of the system card cage.
 Operator control panel assembly, which includes the control panel, the LCD display,
and the floppy drive.
 CD-ROM drive.
 Cooling section containing two fans.
 StorageWorks shelf.

System Overview
DIGITAL Server 5300 1–3
Cover Interlock
The system has a single cover interlock switch tripped by the top cover. To override the
cover interlock, use a suitable object to close the interlock circuit. Disk damage will
result if the system is run with the top cover off.
Figure 1-2 Cover Interlock Circuit
Power Supply
Motherboard DC_ENABLE_L
Cover
Interlock
Cover
Interlock
Switch
OCP
Push button
ON/OFF
J30
J7
J2
Switch
pack
PKW0503-97
__________________________ Note_____________________________
The cover interlock must be engaged to enable power-up.
____________________________________________________________

System Overview
1–4 DIGITAL Server 5300
Operator Control Panel and Drives
The control panel includes the On/Off, Halt, and Reset buttons and an LCD
display.
Figure 1-3 Control Panel Assembly
PKW-0501-97
123
CD-ROM
Floppy
OCP Display
OCP display. The OCP display is a 16-character LCD that indicates status during power-
up and self-test. While the operating system is running, the LCD displays the system type.
Its controller is on the XBUS.
CD-ROM. The CD-ROM drive is used to load software, firmware, and updates. Its
controller is on PCI1 on the PCI backplane on the system motherboard.
Floppy disk. The floppy drive is used to load software. The floppy controller is on the
XBUS on the PCI backplane on the system motherboard.

System Overview
DIGITAL Server 5300 1–5
 On/Off button. Powers the system on or off. When the LED to the right of the button is
lit, the power is on. The On/Off button is connected to the power supplies through the
system interlock and the RCM logic.
 Reset button. Initializes the system.
 Halt button. When the halt button is pressed, different results are manifest depending
upon the state of the machine.
To get to the SRM console, press the Halt button and then press the Reset button.
(Pressing the Halt button when the system is running Windows NT causes a “halt
assertion” flag to be set in the firmware. When Reset is pressed the console reads the “halt
assertion” flag and ignores environment variables that would cause the system to boot.)
Function of the Halt button is complex because it depends upon the state of the machine
when the button is pressed. See “Halt Button Functions” in Chapter 7 for a full discussion
of the Halt button.

System Overview
1–6 DIGITAL Server 5300
System Consoles
There are two console programs: the SRM console and the AlphaBIOS
console.
_____________________________Note ____________________________
NOTE: The console prompt displays only after the entire power-up sequence is
complete. This can take up to several minutes if the memory is very large.
______________________________________________________________
AlphaBIOS Boot Menu
On systems running the Windows NT operating system, the Boot menu is displayed when
the AlphaBIOS console is invoked (see Figure 1-4).
Figure 1-4 AlphaBIOS Boot Menu
AlphaBIOS 5.32
Please select the operatin
g
s
y
stem to start:
Press <F2> to enter SETUP
Windows NT Server 4.0
Use and to move the hi
g
hli
g
ht to
y
our choice.
Press Enter to choose.
ML014366
DIGITAL Server 5300
diig tal
SRM Console
The SRM console is a command-line interface that provides support for examining and
modifying the system state and configuring and testing the system. The SRM console can
be run from a serial terminal or a graphics monitor. The following console prompt is
displayed whenever the SRM console is invoked:
P00>>>

System Overview
DIGITAL Server 5300 1–7
AlphaBIOS Console
The AlphaBIOS console is a menu-based interface that supports the Microsoft Windows
NT operating system. AlphaBIOS is used to set up operating system selections, boot
Windows NT, and display information about the system configuration. The EISA
Configuration Utility and the RAID Standalone Configuration Utility are run from the
AlphaBIOS console. AlphaBIOS runs on either a serial or graphics terminal. Windows
NT requires a graphics monitor.
Environment Variables
Environment variables are software parameters that define, among other things, the system
configuration. They are used to pass information to different pieces of software running in
the system at various times.
Refer to Chapter 7 of this guide for a list of the environment variables used to configure a
system.
Refer to your system User’s Guide for information on setting environment variables.
Most environment variables are stored in the NVRAM that is placed in a socket on the
system motherboard. Even though the NVRAM can be removed and replaced on a new
system motherboard, it is recommended that you keep a record of the environment
variables for each system that you service. Some environment variable settings are lost
when a module is swapped and must be restored after the new module is installed. Refer
to Chapter 7 for a convenient worksheet for recording environment variable settings.

System Overview
1–8 DIGITAL Server 5300
System Architecture
Alpha microprocessor chips are used in these systems. The CPU, memory,
and the I/O modules are connected to the system motherboard.
Figure 1-5 Architecture Diagram
´
XBUS
Xceivers
I2C Bus
Interface
Mouse/
Keyboard
Combo I/O:
serial ports
parallel port
floppy cntrl
Real-Time
Clock
BDATA
Xceivers
XBUS
EISA
Bus
PKW0502-97
PCI Bus 1
System Bus
Memory
Pair
CPU
PCI Slot
PCI Slot
PCI Bus 0
System to
PCI Bus
Bridge 0
IOD0
System to
PCI Bus
Bridge 1
IOD1
PCI Slot
PCI Slot
EISA
Bridge
PCI Slot
PCI Slot
EISA Slot
128-Bit Data Bus + 16 ECC and 40-Bit Command/Address Bus
64 Bits
64 Bits
System
Motherboard
Flash
ROM
2MB
NVRAM
8Kx8
Note: When the EISA/ISA slot
on PCI Bus 0 is used, the last
PCI slot on PCI Bus 1 is not
available.

System Overview
DIGITAL Server 5300 1–9
Both systems use the Alpha chip for the CPU. The CPU, memory, and I/O devices
connect to the system motherboard. On the system motherboard is:
• The system bus
• Two system bus to PCI bus chip sets that bridge two PCI buses to the system bus
• Two 64-bit PCI buses with three PCI options slots each (5 64-bit PCI slots; 1 32-bit
PCI slot)
• One EISA/ISA bus bridged to one of the PCIs (If an EISA/ISA option is used, one PCI
slot cannot be used)
• One CD-ROM controller built in to the other PCI
• One EISA/ISA to XBUS bridge to the built-in XBUS options
A fully configured system can have two CPUs, eight DIMM memory pairs, and a total of
six I/O options. The I/O options can be all PCI options or a combination of PCI options
and a single EISA/ISA option.
The system bus has a 144-bit data bus, protected by 16 bits of ECC, and a 40-bit
command/address bus, protected by parity. The bus speed is set to 66.6 MHz. The 40-bit
address bus can create one terabyte of addresses (that’s a million million). The bus
connects CPUs, memory, and the system bus to PCI bus bridge(s).
There is a cache external to the CPU chip on CPU modules. The Alpha chip has an 8-
Kbyte instruction cache (I-cache), an 8-Kbyte write-through data cache (D-cache), and a
96-Kbyte, write-back secondary data cache (S-cache). The cache system is write-back.
The system supports up to two CPUs.
Memory on these systems is constructed of DIMM memory pairs placed onto two memory
modules called riser cards. The riser cards are placed into the two memory slots on the
system motherboard. One member of a DIMM pair is placed onto one riser card, and the
other member is placed onto another riser card. Each riser card drives half of the system
bus, along with the associated ECC bits. Memory pairs consist of two synchronous
DIMMs of the same size and are placed into the same slot on each riser card.
The system bus-to-PCI bus bridge chip set translates system bus commands and data
addressed to I/O space to PCI commands and data. It also translates PCI bus commands
and data addressed to system memory or CPUs to system bus commands and data. The
PCI bus is a 64-bit wide bus used for I/O.
Logic and sensors on the system motherboard monitor power status and the system
environment (temperature and fan speeds).