Compaq AlphaPC 164SX Technical Reference Manual

Compaq Computer Corporation

AlphaPC 164SX Motherboard
Technical Reference Manual

Order Number: EC–R57EB–TE

Revision/Update Information: This is a revised document. It supersedes the

AlphaPC 164SX Motherboard Technical
Reference Manual, EC–R57EA–TE.

October 1998

The informatio n in this publicati on is subject to change without notice.

COMPAQ COMPUTER CORPORATION SHALL NOT BE LIABLE FOR TECHNICAL OR EDITORIAL
ERRORS OR OMISSIONS CONTAINED HEREIN, NOR FOR INCIDENTAL OR CONSEQUENTIAL DAM­AGES RESULTING FROM THE FURNISHING, PERFORMANCE, OR USE OF THIS MATERIAL. THIS
INFORMATION IS PROVIDED "AS IS" AND COMPAQ COMPUTER CORPORATION DISCLAIMS ANY
WARRANTIES, EXPRESS, IMPLIED OR STATUTORY AND EXPRESSLY DISC LA IMS THE IMPLIED WAR­RANTIES OF MERCHANTABILITY, FITNESS FOR PARTICULAR PURPOSE, GOOD TITLE AND AGAINST
INFRINGEMENT .

This publication contains informat ion protected by copyright. No part of this public a ti on m ay be photocopied or
reproduced in any form without prior written con s ent from Compaq Com puter Corporation .

©1998 Compaq Comp uter Corporation. All ri ght s rese rved. Printed in U.S.A.

AlphaPC, COMP AQ, DECchip, DIGITAL, DIGITAL UNIX, the Compaq logo, and the DIGIT AL logo registered in
United States Patent and Trademark Office.

Altera is a registered trademark of Altera Corporation.
Cypress and hyper Ca che are trademar ks of Cypress Semiconduct or Corporation.
GRAFOIL is a registered trademark of Uni on Ca rbide Corporation.
IEEE is a registered tra demark of The Institute of Electrical and Ele ct roni cs Engineers, Inc.
Intel is a registered trademark of Intel Corporation.
Microsoft and Visual C++ are regi ste red trademarks and Windows NT is a tradem ark of Microsoft Corpora ti on.
SMC and Standard Microsy ste ms a re registered trademark s of Stan dard Microsystems Corp ora tion.
UNIX is a registered trade m ark in the United States an d other countries, licensed exclusively through
X/Open Company Ltd.

Other product names mentioned herein may be trademarks and/or registered trademarks of their respective
companies.

iii

Contents

Preface

1 Introduction

1.1 System Components and Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

1.1.1 21174 Core Logic Chip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

1.1.2 Memory Subsystem. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

1.1.3 L2 Bcache Subsystem Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

1.1.4 PCI Interface Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

1.1.5 ISA Interface Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

1.1.6 Miscellaneous Logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

1.2 Software Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

1.2.1 AlphaBIOS Windows NT Firmware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

1.2.2 Alpha SRM Console Firmware. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

1.2.3 Motherboard Software Developer’s Kit (SDK). . . . . . . . . . . . . . . . . . . . . . . . 1-6

1.3 Hardware Design Support. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

2 System Configuration and Connectors

2.1 AlphaPC 164SX Configuration Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

2.2 CPU Speed Selection (CF[6:4]) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

2.3 Bcache Size Switches (CF0 and CF1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

2.4 Password Bypass (CF2). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

2.5 Fail-Safe Booter (CF7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

2.6 Mini-Debugger (CF3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

2.7 AlphaPC 164SX Connector Pinouts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

2.7.1 PCI Bus Connector Pinouts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

2.7.2 ISA Expansion Bus Connector Pinouts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8

2.7.3 SDRAM DIMM Connector Pinouts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9

2.7.4 EIDE Drive Bus Connector Pinouts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10

2.7.5 Diskette (Floppy) Drive Bus Connector Pinouts. . . . . . . . . . . . . . . . . . . . . . . 2-11

2.7.6 Parallel Bus Connector Pinouts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11

iv

2.7.7 COM1/COM2 Serial Line Connector Pinouts. . . . . . . . . . . . . . . . . . . . . . . . . 2-12

2.7.8 Keyboard/Mouse Connector Pinouts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12

2.7.9 SROM Test Data Input Connector Pinouts . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13

2.7.10 Input Power Connector Pinouts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13

2.7.11 Enclosure Fan Power Connector Pinouts . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13

2.7.12 Microprocessor Fan Power Connector Pinouts. . . . . . . . . . . . . . . . . . . . . . . 2-14

2.7.13 Soft Power Connector Pinouts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14

2.7.14 Multipurpose Connector Pinouts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14

3 Power and Environmental Requirements

3.1 Power Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

3.2 Environmental Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

3.3 Board Dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

3.3.1 ATX Hole Specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3

3.3.2 ATX I/O Shield Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4

4 Functional Description

4.1 AlphaPC 164SX Bcache Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

4.2 21174 Core Logic Chip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

4.2.1 21174 Chip Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

4.2.2 Main Memory Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

4.2.3 PCI Devices. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5

4.2.4 PCI/ISA Bridge Chip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6

4.2.5 PCI Expansion Slots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6

4.3 ISA Bus Devices. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6

4.3.1 Combination Controller Chip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7

4.3.2 ISA Expansion Slots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8

4.3.3 ISA I/O Address Map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8

4.3.4 Flash ROM Address Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9

4.4 Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9

4.5 System Clocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12

4.6 Reset and Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14

4.7 DC Power Distribution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15

4.8 Serial ROM and Debug Port Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16

5 Upgrading the AlphaPC 164SX

5.1 Configuring SDRAM Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

5.2 Upgrading SDRAM Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2

5.3 Increasing Microprocessor Speed. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3

5.3.1 Preparatory Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3

v

5.3.2 Required Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3

5.3.3 Removing the 21164PC Microprocessor. . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4

5.3.4 Installing the 21164PC Microprocessor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4

A Support, Products, and Documentation

A.1 Customer Support. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1

A.2 Supporting Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2

A.2.1 Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2

A.2.2 Thermal Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2

A.2.3 Power Supply. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2

A.2.4 Enclosure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-3

A.3 Alpha Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-3

A.4 Alpha Documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-4

A.5 Third–Party Documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-5

Index

vi

Figures

1–1 AlphaPC 164SX Functional Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

2–1 AlphaPC 164SX Switch/Connector/Component Location. . . . . . . . . . . . . . . . . . . 2-2

2–2 AlphaPC 164SX Configuration Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

2–3 Multipurpose Connector Pinouts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-15

3–1 ATX Hole Specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3

3–2 ATX I/O Shield Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4

4–1 AlphaPC 164SX L2 Bcache Array . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

4–2 Main Memory Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

4–3 AlphaPC 164SX PCI Bus Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5

4–4 AlphaPC 164SX ISA Bus Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8

4–5 Interrupt Request Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10

4–6 AlphaPC 164SX System Clocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-13

4–7 System Reset and Initialization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14

4–8 AlphaPC 164SX Power Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15

5–1 Fan/Heat-Sink Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5

vii

Tables

1–1 AlphaPC 164SX SDRAM Memory Configurations . . . . . . . . . . . . . . . . . . . . . . . . 1-3

2–1 AlphaPC 164SX Switch/Connector/Component List . . . . . . . . . . . . . . . . . . . . . . . 2-3

2–2 PCI Bus Connector Pinouts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

2–3 ISA Expansion Bus Connector Pinouts (J22, J23) . . . . . . . . . . . . . . . . . . . . . . . . 2-8

2–4 SDRAM DIMM Connector Pinouts (J7 through J10). . . . . . . . . . . . . . . . . . . . . . . 2-9

2–5 EIDE Drive Bus Connector Pinouts (J5, J6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10

2–6 Diskette (Floppy) Drive Bus Connector Pinouts (J11). . . . . . . . . . . . . . . . . . . . . . 2-11

2–7 Parallel Bus Connector Pinouts (J13). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11

2–8 COM1/COM2 Serial Line Connector Pinouts (J3). . . . . . . . . . . . . . . . . . . . . . . . . 2-12

2–9 Keyboard/Mouse Connector Pinouts (J4). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12

2–10 SROM Test Data Input Connector Pinouts (J21) . . . . . . . . . . . . . . . . . . . . . . . . . 2-13

2–11 Input Power Connector Pinouts (J2). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13

2–12 Enclosure Fan (+12 V dc) Power Connector Pinouts (J16) . . . . . . . . . . . . . . . . . 2 -13

2–13 Microprocessor Fan Power Connector Pinouts (J14) . . . . . . . . . . . . . . . . . . . . . . 2-14

2–14 Soft Power Connector Pinouts (J1). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14

2–15 Multipurpose Connector Pinouts (J20) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14

3–1 Power Supply DC Current Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

3–2 AlphaPC 164SX Motherboard Environmental Requirements . . . . . . . . . . . . . . . . 3-2

4–1 ISA I/O Address Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8

4–2 AlphaPC 164SX System Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10

4–3 ISA Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11

5–1 AlphaPC 164SX SDRAM Memory Configurations . . . . . . . . . . . . . . . . . . . . . . . . 5-2

ix

Preface

Overview

This manual desc ri bes t he Al phaPC 164SX motherboard, a boa rd for computing sys­tems based on the Alpha 21164PC microprocessor and the 21174 core logic chip.

Audience

This manual is intended for system designers and others who use the AlphaPC
164SX motherboard to design or evaluate computer systems based on the Alpha
21164PC microprocessor and the 21174 core logic chip.

Scope

This manual describes the features, configuration, functional operation, and inter­faces of the AlphaPC 164SX motherboard. This manual does not include specific
bus specifications (for example, PCI or ISA buses). Additional information is avail­able in the AlphaPC 164SX schematics, program source files, and the appropriate
vendor and IEEE specifications. See Appendix A for information on how to order
related documentation and obtain additional technical support.

Manual Organization

As outlined on the next page, this manual includes the following chapters, appen­dixes, and an index.

x

• Chapter 1, Introduction, is an overview of the AlphaPC 164SX motherboard,

including its components, features, and uses.

• Chapter 2, System Configuration and Connectors, describes the user-environ-

ment configuration , board connector s and functions , and switch funct ions. It also
identifies switch settings and connector locations.

• Chapter 3, Power and Environmental Requirements, describes the AlphaPC

164SX power and environmental requirements and provides board dimensions.

• Chapter 4, Functional Description, provides a functional description of the

AlphaPC 164SX motherboard, including the 21174 core logic chip, L2 backup
cache (Bcache) and memory subsystems, system interrupts, clock and power
subsystems, and peri pheral compon ent intercon nect (P CI) and Indus try Standa rd
Architecture (ISA) devices.

• Chapter 5, Upgrading the AlphaPC 164SX, describes how to upgrade the

AlphaPC 164SX motherboard’s SDRAM memory and microprocessor speed.

• Appendix A, Support, Products, and Documentation, lists sources for compo-

nents and accessories not included with the AlphaPC 164SX motherboard and
describes how to obtain information and technical support, and how to order
products and associated literature.

Conventions

This section defines product-specific terminology, abbreviations, and other conven­tions used throughout this manual.

Abbreviations

•

Register Access

The following list describes the register bit and field abbreviations:

Bit/Field Abbreviation Description

RO (read only) Bits and fields specified as RO can be read but not written.
RW (read/write) Bits and fields specified as RW can be read and written.
WO (write only) Bits and fields specified as WO can be written but not read.

xi

• Binary Mult iples

The abbreviations K, M , and G (kil o, mega, and giga) r eprese nt bina ry multi ples
and have the following values.

For example:

Addresses

Unless otherwise noted, all addresses and offsets are hexadecimal.

Bit Notation

Multiple-bit fields can include contiguous and noncontiguous bits contained in
brackets ([]). Multiple contiguous bits are indicated by a pair of numbers separated
by a colon (:). For example, [9:7,5,2:0] specifies bits 9,8,7,5,2,1, and 0. Similarly,
single bits are frequently indicated with brackets. For example, [27] specifies bit 27.

Caution

Cautions indicate potential damage to equipment, software, or data.

Data Field Size

The term INTnn, wher e nn is one of 2, 4, 8, 16, 32, or 64, refers to a data field of
nn contiguous NATURALLY ALIGNED bytes. For example, INT4 refers to a

NATURALLY ALIGNED longword.

Data Units

The following data-unit terminology is used throughout this manual.

K

=2

10

(1024)

M

=2

20

(1,048,576)

G

=2

30

(1,073,741,824)

2KB = 2 kilobytes

=2 × 2

10

bytes

4MB = 4 megabytes

=4 × 2

20

bytes

8GB = 8 gigabytes

=8 × 2

30

bytes

Term Words Bytes Bits Other

Byte ½18—
Word 1 2 16 —
Longword/Dword 2 4 32 Longword

xii

Note

Notes emphasize particularly important information.

Numbering

All numbers are decimal or hexadecimal unless otherwise indicated. The prefix 0x
indicates a hexadecimal number. For example, 19 is decimal, but 0x19 and 0x19A
are hexadecimal (also see Addresses). Otherwise, the base is indicated by a sub­script; for example, 100

2

is a binary number.

Ranges and Extents

Ranges are specif ied by a pair o f number s separ ated b y two periods ( ..) and are inclu ­sive. For example, a range of integers 0..4 includes the integers 0, 1, 2, 3, and 4.

Extents are specified by a pair of numbers in brackets ([]) separated by a colon (:)
and are inclusive. Bit fields are often specified as extents. For example, bits [7:3]
specifies bits 7, 6, 5, 4, and 3.

Register and Memory Figures

Register figures have bit and field position numbering starting at the right (low
order) and increasing to the left (high order).

Memory figures have addresses starting at the top and increasing toward the bottom.

Quadword 4 8 64 2 Longwords
Octaword 8 16 128 2 Quadwords
Hexword 16 32 256 2 Octawords

Term Words Bytes Bits Other

xiii

Signal Names

All signal names are printed in boldface type. Signal names that originate in an
industry-standard specification, such as PCI or IDE, are printed in the case as found
in the specification (usually uppercase). Active-high signals are indicated by the _h
suffix. Active-low signals have the _l suffix, a pound sign “#” appended, or a “not”

overscore bar. Signals with no suf fi x ar e considered high-asser te d si gnal s. For exam­ple, signals data_h[127:0] and cia_int are active-high signals. Signals mem_ack_l,
FRAME#, and RESET

are active-low signals.

UNPREDICTABLE and UNDEFINED

Throughout this manual the terms UNPREDICTABLE and UNDEFINED are used.
Their meanings are quite different and must be carefully distinguished.

In particul ar, only priv il eg ed s of tw are (th at is, s of twa re ru nn ing in kern el mod e )
can trigger UNDEFI NED operations. Unprivileged software cannot trigger
UNDEFINED operat ion s. Howe ver, either privileged or unpri vileged software c an
trigger UNPREDICTABLE results or occurrences.

UNPREDICTABLE results or occurrences do not disrupt the basic operation of the
processor. The processor continues to execute instructions in its normal manner. In
contrast, UNDEFINED operations can halt the processor or cause it to lose informa­tion.

The terms UNPREDICTABLE and UNDEFINED can be further described as fol­lows:

• UNPREDICTABLE

– Results or occurrences specified as UNPREDICTABLE might vary

from moment to moment, impl ementation to im plementation, and
instruction to instruction within implementations. Software can never
depend on results specified as UNPREDICTABLE.

– An UNPREDICT ABLE r esult might acquir e an arbi trar y valu e that is

subject to a few constraints. Such a result might be an arbitrary func­tion of the input operands or of any state information that is accessi­ble to the process in its current access mode. UNPREDICTABLE
results may be unchanged from their previous values.

Operations that produce UNPREDICTABLE results might also pro­duce exceptions.

xiv

– An occurrence specified as UNPREDICTABLE may or may not hap-

pen based on an arbitrary choice function. The choice function is
subject to the s ame c onstraints as are UNPREDI CTABLE results a nd
must not constitute a security hole.

Specifically, UNPREDICTABLE results must not depend upon, or be
a function of, the contents of memory locations or registers that are
inaccessible to the current process in the current access mode.

Also, operations that mig ht produce UNPREDI CTABLE results must
not write or modify the contents of memory locations or registers to
which the current process in the current access mode does not have
access. They must also not halt or hang the system or any of its com­ponents.

For example, a secur ity hole would exist i f so me UNPREDICTABLE
result depended on the value of a register in another process, on the
contents of processor temporary registers left behind by some pr evi­ously running process, or on a sequence of actions of diff erent pro­cesses.

• UNDEFINED

– Operations specified as UNDEFINED can vary from moment to

moment, implementation to implementation, and instruction to
instruction within implementations. The operation can vary in effect
from nothing, to stopping system operation.

– UNDEFINED operations can halt the processor or cause it to lose

information. However, UNDEFINED operations must not cause the
processor to hang, that is, reach an unhalted state from which there is
no transition to a normal state in which the machine executes instruc­tions. Only privileged software (that is, software running in kernel
mode) can trigger UNDEFINED operations.

Introduction 1–1

1

Introduction

This chapter provides an overview of the AlphaPC 164SX motherboard, including
its components, features, and uses. The motherboard is a module for computing sys­tems based on the 21174 core logic chip.

The AlphaPC 164SX provides a single-board hardware and software development
platform for t he desig n, integrat ion, a nd analys is of s upporting logic a nd subsys tems.
The board also provides a platform for PCI I/O device hardware and software devel­opment.

1.1 System Components and Features

The AlphaPC 164SX is implemented in industry-standard parts and uses an Alpha
21164PC microprocessor running at 400 or 533 MHz. Figure 1–1 shows the board’s

functional components.

1–2 Introduction

System Components and Features

Figure 1–1 AlphaPC 164SX Functional Block Diagram

Alpha 21164PC

Microprocessor

DECchip 21174-CA

Control, I/O Interface,

and Address

1MB, L2

Bcache

Quick Switches

Index
Control

18

Bcache Tag

10

128

Data

16

Address
Commands

Control

Flash ROM

128-Bit Data

168-Pin
Unbuffered
SDRAM DIMM

Sockets (× 4)

Support

– Synthesizer

PCI-to-ISA

Bridge

EIDE

Controller

Combination

Controller

Address/Control

PCI

2 Dedicated 32-Bit PCI Slots
2 Dedicated 64-Bit PCI Slots
2 Dedicated ISA Slots

Diskette
Parallel Port
2 Serial Ports

4 Devices

Introduction 1–3

System Components and Features

1.1.1 21174 Core Logic Chip

The Alpha 21164PC microprocessor is supported by the 21174 core logic chip,

which provides an interface between three units—memory, the PCI bus, and the
21164PC (along with flash ROM). This core logic chip is the interf ace between the
21164PC microprocessor, main memory (addressing and control), and the PCI bus.

Quick switches provide the memory interface data path isolation.
The 21174 includes the majority of functions necessary to develop a high-perfor-

mance PC or workstation, requiring minimum discrete logic on the module. It pro­vides flexible and generic functions to allow its use in a wide range of systems.

1.1.2 Memory Subsystem

The synchronous dynamic random-access memory (SDRAM) is contained in two
banks of dual inline memory modules (DIMMs). Single- or double-sided DIMMs
may be used. Two DIMMs provide 32Mb to 256MB of memory, while four DIMMs
provide up to 512MB. Table 1–1 lists the DIMM sizes tested and the corresponding
main memory si ze for 128-bit arrays.

Note: Each DIMM can be 72 bits or 64 bits wide, with 100 MHz or faster

speed.

Table 1–1 AlphaPC 164SX SDRAM Memory Configurations

(Sheet 1 of 2)

Bank 0

1

Bank 1

1

Total Memory J7 J8 J9 J10

32MB 2Mb × 72 2Mb × 72 ——

64MB 2Mb

× 72 2Mb × 72 2Mb × 72 2Mb × 72

4Mb

× 72 4M b × 72 ——

96MB 4Mb

× 72 4Mb × 72 2Mb × 72 2Mb × 72

128MB 4Mb

× 72 4Mb × 72 4Mb × 72 4Mb × 72

8Mb

× 72 8M b × 72 ——

160MB 8Mb

× 72 8M b × 72 2Mb × 72 2Mb × 72

1–4 Introduction

System Components and Features

1.1.3 L2 Bcache Subsystem Overview

The AlphaPC 164SX board-level L2 backup cache (Bcache) is a 1MB, direct­mapped, synchronous, pipelined burst SROM with a 128-bit data path. The board is
capable of handling an L2 cache size of 2MB. See Section 2.3 for more information
about the Bcache.

1.1.4 PCI Interface Overview

The AlphaPC 164SX PCI interface, with a 33-MHz data transfer rate, is the main
I/O bus for the majority of functions (SCSI interface, graphics accelerator, and so
on). PCI-EIDE support is provided by an onboard controller chip (Cypress
CY82C693U-NC), which also prov ide s a PCI- to-ISA bridge, a mouse and keyboard
controller, and a time-of-year (TOY) clock.

The PCI bus has four dedicated PCI expansion slots (two 64-bit and two 32-bit).

1.1.5 ISA Interface Overview

The ISA bus provides the following system support functions:

• Two expansion slots.

• An SMC FDC37C669 combination controller chip that provides:

– A diskette controller
– Two universal asynchronous receiver-transmitters (UARTs) with full

modem control

– A bidirec t ional parallel port

1

64-bit-wide DIMMs can also be used.

Bank 0

1

Bank 1

1

Total Memory J7 J8 J9 J10

192MB 8Mb × 72 8Mb × 72 4Mb × 72 4Mb × 72

256MB 8Mb

× 72 8Mb × 72 8Mb × 72 8Mb × 72

16Mb

× 72 16Mb × 72 ——

512MB 16Mb

× 72 16Mb × 72 16Mb × 72 16Mb × 72

Table 1–1 AlphaPC 164SX SDRAM Memory Configurations

(Sheet 2 of 2)

Introduction 1–5

Software Support

1.1.6 Miscellaneous Logic

The AlphaPC 164SX contains the following miscellaneous components:

• Operating system sup port — through a 1MB f lash ROM that contain s supporting

firmware.

• Synthesizer for clocks:

– A clock synthesizer (MC12439) provides a programmable 400- and

533-MHz cl o ck so ur ce to th e 21164PC microproce ss or. The microp roc es -

sor supplies a cl ock to the sy stem PLL/clock buffer for th e 21174.
– The 21174 core logic chip provides the SDRAM and PCI clocks.
– A 14.318-MHz crystal and frequency generator provide a clock source for

the combination controller (FDC37C669) and the PCI-to-ISA bridge

(CY82C693U-NC). The controller’s onchip generator then provides other

clocks as needed.
– A 32-kHz crystal provides the TOY clock source.

• Flash ROM:

– Fail-safe booter
– Boot code
– BIOS: Windows NT or Alpha SRM console

• Altera EPM7064LC44-7 for DMA boundary issue.

1.2 Software Support

The support elements described in this section are either included with the
AlphaPC 164SX or are available separately.

1.2.1 AlphaBIOS Windows NT Firmware

The AlphaPC 164SX motherboard ships with AlphaBIOS firmware and online docu­mentation that describes how to configure the firmware for Windows NT. This firmware
initializes the system and enables you to install and boot the Windows NT operating
system. The AlphaBIOS firmware resides in the flash ROM on the 21A05-A0 variation
of the AlphaPC 164SX motherboard. Binary images of the AlphaBIOS firmware are
included in the motherboard Software Developer’ s Kit (SDK), along with a license

describing the terms for use and distribution.

1–6 Introduction

Hardware Design Support

1.2.2 Alpha SRM Console Firmware

The Alpha SRM Console firmware is required to install and boot DIGITAL UNIX
on the AlphaPC 164SX. This Alpha firmware comes factory installed in the 21A05­A1 variation of the AlphaPC 164SX. When installed, this firmware occupies the
flash blocks reserve d for the pri m ary firmwar e. Binary im ages of the Alpha SRM
Console firmware are included in the SDK and Firmware Update compact disk,
along with a license describing the terms for use and distribution.

1.2.3 Motherboard Software Developer’s Kit (SDK)

The SDK and Firmware Update is designed to provide an environment for develop­ing software for Alpha mot herbo ard pr oducts . It i s als o speci ally suit ed for low-l evel
software development and hardware debug for other Alpha microprocessor-based
designs.

The following list includes some of the components of the SDK:

• The Alpha Motherboard Debug Monitor firmware with source code

• Power-up initialization SROM and SROM Mini-Debugger with source code

• Sample PALcode sources modeled after DIGITAL UNIX with source code

• Fail-safe booter with source code

• Various additional tools with source code

The following development platforms are supported by the SDK:

• DIGITAL UNIX with the C Developer’s Extensions

• Windows NT (Alpha) with the Microsoft Visual C++ Development System for

Alpha

• Windows NT (Intel) with the Microsoft Visual C++ Development System and

Tools provide limited support. This environment is currently useful for SROM
and PALcode development only.

1.3 Hardware Design Support

The full design database, including schematics and source files, is supplied. User
documentation is also included. The database allows designers with no previous
Alpha architecture experience to successfully develop a working Alpha system with
minimal assistance.

System Configuration and Connectors 2–1

2

System Configuration and Connectors

This chapter describes the AlphaPC 164SX configuration, board connectors and
functions, and switch functions. It also identifies switch and connector locations.

The AlphaPC 164SX uses switches to implement configuration parameters such as

system speed and bo ot pa ra meters. These switches must b e con fi gur ed f or the user’s
environment. Onboard connectors are provided for the I/O interfaces, DIMMs, and
serial and parallel peripheral ports.

Figure 2–1 shows the board outlines and identifies the location of switches, connec­tors, and major components. Table 2–1 lists and defines these items.

2–2 System Configuration and Connectors

Figure 2–1 AlphaPC 164SX Switch/Connector/Component Location

XU59

Q8

J1

J2

J3

J4

J5 J6

J7 J8 J9

J10

J11

J13

21164PC

U31

J14

J16

J15

J17

J18

J19

J20

J21

SW1 J22

J23

Q5

Q4

Q7

XB1

X2

X1

X3

U47

U39

21174

U33

U30

U46

U45

U25

U27

U23

U24

U17

U18

U12

U13

U7

U5

U3

U4

U1

U28

U32

U10 U11

U20 U21 U22

U48

U49

U50

U52

U51

U53

U54

U55

U40

U41 U42

U43

U44

U2

U8

U9

U6

U16

U14

U15

U19

U26

U29

U34

U35

U36

U37 U38

U56

System Configuration and Connectors 2–3

Table 2–1 AlphaPC 164SX Switch/Connector/Component List

Item No. Description Item No. Description

XB1 RTC battery (CR2032) J20 LEDs/speaker/buttons connectors
J1 Soft power connector J21 SROM test port connector
J2 Input power (+3 V, +5 V, -5 V, +12 V,

-12 V)

J22 ISA slot 1

J3 COM1/COM2 (DB9) connectors J23 ISA slot 0
J4 Keyboard/mouse connectors SW1 Configuration switchpack
J5 EIDE drive 2/3 connector U48 System clock PLL (CY2081)
J6 EIDE drive 0/1 connector U10, U11,

U20, U22

L2 cache data SRAMs

J7 SDRAM DIMM 0 [0:63] connector U21 L2 cache tag SRAM
J8 SDRAM DIMM 1 [64:128] connector U33 21174 core logic chip
J9 SDRAM DIMM 2 [0:63] connector U19, U26,

U29

Memory address/control buffers

J10 SDRAM DIMM 3 [64:128] connector U1, U3, U4,

U5, U7,
U12, U13,
U17, U18,
U23, U24,
U25, U27

Data switches

J11 Diskette (floppy) drive con nector U40 to U43 Interrupt shift registers
J13 Parallel I/O connector U30 Flash ROM (1MB)
J14 Microprocessor fan/fan sense connector U46 PCI-ISA Bridge

(CY82C693U-NC)
J15 PCI slot 3 (32-bit) U36 to U38 IDE buffers
J16 Fan power, enclosure (+12 V) U47 Combination controller

(FDC37C669)
J17 PCI slot 2 (32-bit) U2, U28,

U32

Reg-reg cache isolate logic

J18 PCI slot 1 (64-bit) U31 Microprocessor, socketed

(Alpha 21164PC)
J19 PCI slot 0 (64-bit) U45 Microprocessor clock synthesizer

(MC12439)

2–4 System Configuration and Connectors

AlphaPC 164SX Configuration Switches

2.1 AlphaPC 164SX Configuration Switches

The AlphaPC 164SX motherboa rd has a swi tchpac k locat ed at SW1, as s hown previ ­ously in Figure 2–1. The switches set the hardware configuration and boot options.

Figure 2–2 shows the switch functions.

Figure 2–2 AlphaPC 164SX Configuration Switches

2.2 CPU Speed Selection (CF[6:4])

The clock synthesizer at U45 makes it possible to change the frequency of the

microprocessor’s clock output. The switch configuration is set in SW1, CF[6:4].
These three switches set the speed at power-up as listed in Figure 2–2. The
microprocessor frequency divided by the ratio determines the system clock
frequency.

CF Bit: 400 MHz 533 MHz

41 1
51 0
61 1

CF0
CF1
CF2
CF3

CF4
CF5
CF6
CF7

01

Password Bypass: 0 bypasses password protection

1 requires AlphaBIOS password

Fail-Safe Booter: 0: Fail Safe

1: AlphaBIOS or SRM console

Note:

All other combinations
are reserved.

Note: Switch defaults are in bold.

Mini-Debugger: 0 enables Mini-Debugger

1 disables Mini-Debugger

CF Bit: .5MB 1M B 2MB Reserved

00 1 01
10 0 11

System Configuration and Connectors 2–5

Bcache Size Switches (CF0 and CF1)

2.3 Bcache Size Switches (CF0 and CF1)

The Bcache size switches are located at SW1 (CF0 and CF1), as shown in

Figure 2–2. The AlphaPC 164SX is configured with 1MB of Bcache during
production; the other combinations shown in Figure 2–2 (.5MB and 2MB) are for
other implementations.

Note: The standard motherboard (21A05-A0 for Windows NT and 21A05-A1

for DIGITAL UNIX) is manufactu red wi th 64K × 32 data SSRAMs. An
OEM, however, can create an L2 cache in either a 2MB variation, using
128K × 32 data SSRAMs, or a .5MB variation, using 32K × 32 data
SSRAMs.

2.4 Password Bypass (CF2)

AlphaBIOS provides password protection. However, password bypass is provided
for system setup or startup when the AlphaBIOS password is unavailable.

Password bypass is disabled by default, with switch CF2 of SW1 in the on position
(see Figure 2–2). Whe n this functi on is enable d, it disab les the Alph aBIOS password
verification and enables the user to set up or start up their system without the
AlphaBIOS password. Password bypass also clears the password.

To disable this function and require a password, slide CF2 to the on position.

2.5 Fail-Safe Booter (CF7)

The fail-safe booter provides an emergency recovery mechanism when the primary
firmware image cont ai ned in flash memory has been corrupted. When flash memory
has been corrupted, and no image can be loaded safely from the flash, you can run
the fail-safe booter and boot another image from a diskette that is capable of repro­gramming the flash.

For more information about the fail-safe booter, refer to the AlphaPC 164SX

Motherboard Windows NT User’s Manual.

2–6 System Configuration and Connectors

Mini-Debugger (CF3)

2.6 Mini-Debugger (CF3)

The Alpha SROM Mini-Debugger is stored in the flash ROM and is enabled/

disabled by switch CF3. The default position for this switch is on (see Figure 2–2).
When this switch is off, it causes the SROM initialization to trap to the Mini­Debugger after all initialization is complete, but before starting the execution of the
system flash ROM code.

2.7 AlphaPC 164SX Connector Pinouts

This section lists the pinouts of all AlphaPC 164SX connectors. See Figure 2–1 for
connector locations.

2.7.1 PCI Bus Connector Pinouts

Table 2–2 shows the PCI bus connector pinouts.

Table 2–2 PCI Bus Connector Pinouts

(Sheet 1 of 2)

Pin Signal Pin Signal Pin Signal Pin Signal
32-Bit and 64-Bit PCI Connectors (J15, J17, J18, J19)

A1 TRST# A2 +12V A3 TMS A4 TDI
A5 Vdd A6 INTA A7 INTC A8 Vdd
A9 —A10Vdd A11 — A12 Gnd

A13 Gnd A14 — A15 RST# A16 Vdd
A17 GNT# A18 Gnd A19 — A20 AD[30]
A21 +3V A22 AD[28] A23 AD[26] A24 Gnd
A25 AD[24] A26 IDSEL A27 +3V A28 AD[22]
A29 AD[20] A30 Gnd A31 AD[18] A32 AD[16]
A33 +3V A34 FRAME# A35 Gnd A36 TRDY#
A37 STOP# A38 STOP# A39 +3V A40 SDONE
A41 SBO# A42 Gnd A43 PAR A44 AD[15]
A45 +3V A46 AD[13] A47 AD[11] A48 Gnd
A49 AD[09] A50 Not used A51 Not used A52 C/BE#[0]
A53 +3V A54 AD[06] A55 AD[04] A56 Gnd
A57 AD[02] A58 AD[00] A59 Vdd A60 REQ64#
A61 Vdd A62 Vdd B1 -12V B2 TCK
B3 Gnd B4 TDO B5 Vdd B6 Vdd
B7 INTB B8 INTD B9 PRSNT1# B10 —
B11 PRSNT2# B12 Gnd B13 Gnd B14 —

System Configuration and Connectors 2–7

AlphaPC 164SX Connector Pinouts

B15 Gnd B16 CLK B17 Gnd B18 REQ#
B19 Vdd B20 AD[31] B21 AD[29] B22 Gnd
B23 AD[27] B24 AD[25] B25 +3V B26 C/BE#[3]
B27 AD[23] B28 Gnd B29 AD[21] B30 AD[19]
B31 +3V B32 AD[17] B33 C/BE#[2] B34 Gnd
B35 IRDY# B36 +3V B37 DEVSEL# B38 Gnd
B39 LOCK# B40 PERR# B41 +3V B42 SERR#
B43 +3V B44 C/BE#[1] B45 AD[14] B46 Gnd
B47 AD[12] B48 AD[10] B49 Gnd B50 Not used
B51 Not used B52 AD[08] B53 AD[07] B54 +3V
B55 AD[05] B56 AD[03] B57 Gnd B58 AD[01]
B59 Vdd B60 ACK64# B61 Vdd B62 Vdd

64-Bit PCI Connectors Only (J18, J19)

A63 Gnd A64 C/BE#[7] A65 C/BE#[5] A66 Vdd
A67 PAR64 A68 D[62] A69 Gnd A70 D[60]
A71 D[58] A72 Gnd A73 D[56] A74 D[54]
A75 Vdd A76 D[52] A77 D[50] A78 Gnd
A79 D[48] A80 D[46] A81 Gnd A82 D[44]
A83 D[42] A84 Vdd A85 D[40] A86 D[38]
A87 Gnd A88 D[36] A89 D[34] A90 Gnd
A91 D[32] A92 —A93Gnd A94 —

B63 — B64 Gnd B65 C/BE#[6] B66 C/BE#[4]
B67 Gnd B68 D[63] B69 D[61] B70 Vdd
B71 D[59] B72 D[57] B73 Gnd B74 D[55]
B75 D[53] B76 Gnd B77 D[51] B78 D[49]
B79 Vdd B80 D[47] B81 D[45] B82 Gnd
B83 D[43] B84 D[41] B85 Gnd B86 D[39]
B87 D[37] B88 Vdd B89 D[35] B90 D[33]
B91 Gnd B92 — B93 — B94 Gnd

Table 2–2 PCI Bus Connector Pinouts

(Sheet 2 of 2)

Pin Signal Pin Signal Pin Signal Pin Signal

2–8 System Configuration and Connectors

AlphaPC 164SX Connector Pinouts

2.7.2 ISA Expansion Bus Connector Pinouts

Table 2–3 shows the ISA expansion bus connector pinouts.

Table 2–3 ISA Expansion Bus Connector Pinouts (J22, J23)

Pin Signal Pin Signal Pin Signal Pin Signal

1 Gnd 2 IOCHCK# 3 RSTDRV 4 SD7
5 Vdd 6 SD6 7 IRQ9 8 SD5
9 –5V 10 SD4 11 DRQ2 12 SD3
13 –12V 14 SD2 15 ZEROWS# 16 SD1
17 +12V 18 SD0 19 Gnd 20 IOCHRDY
21 SMEMW# 22 AEN 23 SMEMR# 24 SA19
25 IOW# 26 SA18 27 IOR# 28 SA17
29 DACK3# 30 SA16 31 DRQ3 32 SA15
33 DACK1# 34 SA14 35 DRQ1 36 SA13
37 REFRESH# 38 SA12 39 SYSCLK 40 SA11
41 IRQ7 42 SA10 43 IRQ6 44 SA9
45 IRQ5 46 SA8 47 IRQ4 48 SA7
49 IRQ3 50 SA6 51 DACK2# 52 SA5
53 TC 54 SA4 55 BALE 56 SA3
57 Vdd 58 SA2 59 OSC 60 SA1
61 Gnd 62 SA0 63 MEMCS16# 64 SBHE#
65 IOCS16# 66 LA23 67 IRQ10 68 LA22
69 IRQ11 70 LA21 71 IRQ12 72 LA20
73 IRQ15 74 LA19 75 IRQ14 76 LA18
77 DACK0# 78 LA17 79 DRQ0 80 MEMR#
81 DACK5# 82 MEMW# 83 DRQ5 84 SD8
85 DACK6# 86 SD9 87 DRQ6 88 SD10
89 DACK7# 90 SD11 91 DRQ7 92 SD12
93 Vdd 94 SD13 95 MASTER# 96 SD14
97 Gnd 98 SD15 —— ——

System Configuration and Connectors 2–9

AlphaPC 164SX Connector Pinouts

2.7.3 SDRAM DIMM Connector Pinouts

Table 2–4 shows the SDRAM DIMM connector pinouts.

Table 2–4 SDRAM DIMM Connector Pinouts (J7 through J10)1

(Sheet 1 of 2)

Pin Signal Pin Signal Pin Signal Pin Signal

1 Gnd 2 DQ0 3 DQ1 4 DQ2
5 DQ3 6 +3V 7 DQ4 8 DQ5
9 DQ6 10 DQ7 11 DQ8 12 Gnd
13 DQ9 14 DQ10 15 DQ11 16 DQ12
17 DQ13 18 +3V 19 DQ14 20 DQ15
21 CB0 22 CB1 23 Gnd 24 NC
25 NC 26 +3V 27 WE

28 DQMB0

29 DQMB1 30 S0

31 NC 32 Gnd
33 A0 34 A2 35 A4 36 A6
37 A8 38 A10 39 A12 40 +3V
41 +3V 42 CK0 43 Gnd 44 NC
45 S2

46 DQMB2 47 DQMB3 48 NC
49 +3V 50 NC 51 NC 52 CB2
53 CB3 54 Gnd 55 DQ16 56 DQ17
57 DQ18 58 DQ19 59 +3V 60 DQ20
61 NC 62 NC 63 CKE1 64 Gnd
65 DQ21 66 DQ22 67 DQ23 68 Gnd
69 DQ24 70 DQ25 71 DQ26 72 DQ27
73 +3V 74 DQ28 75 DQ29 76 DQ30
77 DQ31 78 Gnd 79 CK2 80 NC
81 NC 82 SDA 83 SCL 84 +3V
85 Gnd 86 DQ32 87 DQ33 88 DQ34
89 DQ35 90 +3V 91 DQ36 92 DQ37
93 DQ38 94 DQ39 95 DQ40 96 Gnd
97 DQ41 98 DQ42 99 DQ43 100 DQ44
101 DQ45 102 +3V 103 DQ46 104 DQ47
105 CB4 106 CB5 107 Gnd 108 NC
109 NC 110 +3V 111 CAS

112 DQMB4

113 DQMB5 114 S1 115 RAS

116 Gnd
117 A1 118 A3 119 A5 120 A7
121 A9 122 BA0 123 A13 124 +3V

2–10 System Configuration and Connectors

AlphaPC 164SX Connector Pinouts

2.7.4 EIDE Drive Bus Connector Pinouts

Table 2–5 shows the EIDE drive bus connector pinouts.

1

Pins 1 through 84 are on the front side and pins 85 through 168 are on the back side.

2

The AlphaPC 164SX uses BA1 as both BA1 and ADDR12. Therefore, four-bank DIMMs using ADDR[11:0]
are the maximum size. (Two-bank DIMMs can use ADDR[12:0].)

3

Pull-down.

125 CK1 126 BA1

2

127 Gnd 128 CKE0

129 S3

130 DQMB6 131 DQMB7 132 PD

3

133 +3V 134 NC 135 NC 136 CB6
137 CB7 138 Gnd 139 DQ48 140 DQ49
141 DQ50 142 DQ51 143 +3V 144 DQ52
145 NC 146 NC 147 PD 148 Gnd
149 DQ53 150 DQ54 151 DQ55 152 Gnd
153 DQ56 154 DQ57 155 DQ58 156 DQ59
157 +3V 158 DQ60 159 DQ61 160 DQ62
161 DQ63 162 Gnd 163 CK3 164 NC
165 SA0 166 SA1 167 SA2 168 +3V

Table 2–5 EIDE Drive Bus Connector Pinouts (J5, J6)

Pin Signal Pin Signal Pin Signal Pin Signal

1 RESET 2 Gnd 3 IDE_D7 4 IDE_D8
5 IDE_D6 6 IDE_D9 7 IDE_D5 8 IDE_D10
9 IDE_D4 10 IDE_D11 11 IDE_D3 12 IDE_D12
13 IDE_D2 14 IDE_D13 15 IDE_D1 16 IDE_D14
17 IDE_D0 18 IDE_D15 19 Gnd 20 NC (key pin)
21 MARQ 22 Gnd 23 IOW

24 Gnd
25 IOR

26 Gnd 27 CHRDY 28 BALE
29 MACK 30 Gnd 31 IRQ 32 IOCS16
33 ADDR1 34 NC 35 ADDR0 36 ADDR2
37 CS0

38 CS1 39 ACT 40 Gnd

Table 2–4 SDRAM DIMM Connector Pinouts (J7 through J10)

1

(Sheet 2 of 2)

Pin Signal Pin Signal Pin Signal Pin Signal

System Configuration and Connectors 2–11

AlphaPC 164SX Connector Pinouts

2.7.5 Diskette (Floppy) Drive Bus Connector Pinouts

Table 2–6 shows the diskette (floppy) drive bus connector pinouts.

2.7.6 Parallel Bus Connector Pinouts

Table 2–7 shows the parallel bus connector pinouts.

Table 2–6 Diskette (Floppy) Drive Bus Connector Pinouts (J11)

Pin Signal Pin Signal Pin Signal Pin Signal

1 Gnd 2 DEN0 3 Gnd 4NC
5Gnd 6 DEN1 7 Gnd 8 INDEX
9 Gnd 10 MTR0 11 Gnd 12 DR1
13 Gnd 14 DR0 15 Gnd 16 MTR1
17 Gnd 18 DIR 19 Gnd 20 STEP
21 Gnd 22 WDATA 23 Gnd 24 WGATE
25 Gnd 26 TRK0 27 Gnd 28 WRTPRT
29 ID0 30 RDATA 31 Gnd 32 HDSEL
33 ID1 34 DSKCHG —— — —

Table 2–7 Parallel Bus Connector Pinouts (J13)

Pin Signal Pin Signal Pin Signal Pin Signal

1 STB 2 PD0 3 PD1 4 PD2
5 PD3 6 PD4 7 PD5 8 PD6
9 PD7 10 ACK 11 BUSY 12 PE
13 SLCT 14 AFD 15 ERR 16 INIT
17 SLIN 18 Gnd 19 Gnd 20 Gnd
21 Gnd 22 Gnd 23 Gnd 24 Gnd
25 Gnd —— —— — —

2–12 System Configuration and Connectors

AlphaPC 164SX Connector Pinouts

2.7.7 COM1/COM2 Serial Line Connector Pinouts

Table 2–8 shows the COM1/COM2 serial line connector pinouts.

2.7.8 Keyboard/Mouse Connector Pinouts

Table 2–9 shows the keyboard/mouse connector pinouts.

Table 2–8 COM1/COM2 Serial Line Connector Pinouts (J3)

COM1 Pin
(Top) COM1 Signal

COM2 Pin
(Bottom) COM2 Signal

1 DCD1 1 DCD2
2 RxD1 2 RxD2
3 TxD1 3 TxD2
4 DTR1 4 DTR2
5 SG1 5 SG2
6 DSR1 6 DSR2
7 RTS1 7 RTS2
8 CTS1 8 CTS2
9 RI1 9 RI2

Table 2–9 Keyboard/Mouse Connector Pinouts (J4)

Keyboard Pin
(Top) Keyboard Signal

Mouse Pin
(Bottom) Mouse Signal

1 KBDATA 1 MSDATA
2NC 2NC
3Gnd 3 Gnd
4 Vdd 4 Vdd
5 KBCLK 5 MSCLK
6NC 6NC

System Configuration and Connectors 2–13

AlphaPC 164SX Connector Pinouts

2.7.9 SROM Test Data Input Connector Pinouts

Table 2–10 shows the SROM test data input connector pinouts.

2.7.10 Input Power Connector Pinouts

Table 2–11 shows the input power connector pinouts.

2.7.11 Enclosure Fan Power Connector Pinouts

Table 2–12 shows the enclosure fan power connector pinouts.

1

This pinout is ATX-compliant.

Table 2–10 SROM Test Data Input Connector Pinouts (J21)

Pin Signal Description

1NC —
2SROM_CLK_L Clock out
3 Gnd —
4NC —
5TEST_SROM_D_L SROM serial data in
6NC —

Table 2–11 Input Power Connector Pinouts (J2)

1

Pin Voltage Pin Voltage Pin Voltage Pin Voltage

1 +3.3 V dc 2 +3.3 V dc 3 Gnd 4+5 V dc
5Gnd 6+5 V dc7 Gnd 8 P_DCOK
9 5 V SB 10 +12 V dc 11 +3.3 V dc 12 –12 V dc

13 Gnd 14 PS_ON 15 Gnd 16 Gnd
17 Gnd 18 –5 V dc 19 +5 V dc 20 +5 V dc

Table 2–12 Enclosure Fan (+12 V dc) Power Connector Pinouts (J16)

Pin Voltage

1 Gnd
2 +12 V dc
3 Gnd

2–14 System Configuration and Connectors

AlphaPC 164SX Connector Pinouts

2.7.12 Microprocessor Fan Power Connector Pinouts

Table 2–13 shows the microprocessor fan power connector pinouts.

2.7.13 Soft Power Connector Pinouts

Table 2–14 shows the soft power connector pinouts.

2.7.14 Multipurpose Connector Pinouts

J20 is a multipurpose connector that provides pins for the following functions:

• System speaker

• LEDs for power and the EIDE drive

• Buttons for reset and halt

Table 2–15 shows the multipurpose connector pinouts, and Figure 2–3 shows the
connector layout.

Table 2–13 Microprocessor Fan Power Connector Pinouts (J14)

Pin Signal Description

1 +12 V dc —
2 FAN_CONN_L Fan connected
3 Gnd —

Table 2–14 Soft Power Connector Pinouts (J1)

Pin Signal Description

1 Input System power on/off
2 Gnd —

Table 2–15 Multipurpose Connector Pinouts (J20)

(Sheet 1 of 2)

Pin Signal Description

1 Gnd —
2 HALT_BUTTON

1

Halt system

3 Gnd —
4 RESET_BUTTON Reset system

5 HD_PU Hard drive power-up
6 HD_LED Pull-up to Vdd

System Configuration and Connectors 2–15

AlphaPC 164SX Connector Pinouts

Figure 2–3 Multipurpose Connector Pinouts

1

The halt button is not used with the Windows NT operating system.

7 — No connection

8 POWER_LED_L Pull-up to Vdd
10, 12, 14, 16 Gnd —

9 SPKR Speaker output
15 Vdd —
11, 13 — No connection

Table 2–15 Multipurpose Connector Pinouts (J20)

(Sheet 2 of 2)

Pin Signal Description

12
3

4
56
78

910

11 12
13 14

15 16

HALT_BUTTON

(See note.)

RESET_BUTTON
HD_LED

POWER_LED_L

HD_PU

SPKR

Vdd

Note: The halt button is not used with Windows NT.

J20

Power and Environmental Requirements 3–1

3

Power and Environmental Requirements

This chapter describes the AlphaPC 164SX power and environmental requirements,
and physical board parameters.

3.1 Power Requirements

The AlphaPC 164SX derives its main dc power from a user-suppli ed power supply.
The board has a total power dissipation of 90 W, excluding any plug-in PCI and I S A
devices. An onboard +5-V t o +2.5- V dc- to- dc con verter is designed to handle 24 A o f

current. Table 3–1 lists the power requi rement for eac h dc s uppl y voltage.
The power supply must supply a dcok signal to the system reset logic. Refer to

Section 4.6 for additional information.

Caution: Fan sensor required. The 21164PC microprocessor cooling fan must

drive an RPM indicator signal. If the airflow stops, the sensor on the
motherboard detects that the RPM has stopped, and resets the system.

1

Values indicated are for an AlphaPC 164SX motherboard with an Alpha 21164PC microproces­sor operating at 533 MHz, with 128MB SDRAM, excluding adap ter cards and disk drives.

Table 3–1 Power Supply DC Current Requirements

Voltage/Tolerance Current

1

+3.3 V dc, ±5% 5.0 A
+5 V dc,

±5% 12.0 A

–5 V dc,

±5% 0.0 A

+12 V dc,

±5% 1.0 A

–12 V dc,

±5% 100.0 mA

3–2 Power and Environmental Requirements

Environmental Requirements

3.2 Environmental Requirements

The 21164PC microprocessor is cooled by a small fan blowing directly into the

chip’s heat sink. The AlphaPC 164SX motherboard is designed to run efficiently by
using only this f an. Add it ion al fans may be necessary depending upon cabin et ry a nd
the requirements of plug-in cards.

The AlphaPC 164SX motherboard is specified to run within the environment listed
in Table 3–2.

3.3 Board Dimensions

The AlphaPC 164SX is an ATX-size printed-wiring board (PWB) with the following
dimensions:

• Length: 30.48 cm (12.0 in ±0.0005 in)

• Width: 24.38 cm (9.6 in ±0.0005 in)

• Height: 6.00 cm (2.4 in)

The board can be used in certain desktop and deskside systems that have adequate
clearance for the 21164PC heat sink and its cooling fan. All ISA and PCI expansion
slots are usable in standard desktop or deskside enclosures.

Table 3–2 AlphaPC 164SX Motherboard Environmental Requirements

Parameter Specification

Operating temperature 10°C to 40°C (50°F to 104°F)
Storage temperature –55°C to 125°C (–67°F to 257°F)
Relative humidity 10% to 90% with maxi mum wet bulb temperature 28°C

(82°F) and minimum dew point 2°C (36°F)

Rate of (dry bulb) temperature
change

11°C/hour

±2°C/hour (20°F/hour ±4°F/hour)

Power and Environmental Requirements 3–3

Board Dimensions

3.3.1 ATX Hole Specification

Figure 3–1 shows the ATX hole specification for the AlphaPC 164SX.

Figure 3–1 ATX Hole Specification

.800

TYP Between
Connectors

.650

.500

.400

4.900

1.612

.600

.625

9.600

8.950

6.100

ISA Connector
(2 Places)

PCI Connector
(4 Places)

1.300

11.100

12.000

FM-06122.AI4

3–4 Power and Environmental Requirements

Board Dimensions

3.3.2 ATX I/O Shield Requirements

Figure 3–2 shows the ATX I/O shield dimensions for the AlphaPC 164SX.

Figure 3–2 ATX I/O Shield Dimensions

11.15

15.47

4.35

17.95

22.95

23.96

29.10

33.10

9.25

3.58

2.45

5.00 TYP

R 1.00

21.36

16.05

68.4

64.9

24.7

16.7

35.5

43.5

74.8

78.2

85.4

87.2

94.4

98.9

64.91

60.26

51.27

42.28

40.48

34.13

25.14

16.15

14.35

8.00

0.99

9.98

11.78

18.13

19.93

28.92

37.91

44.26

46.06

55.05

64.04

70.39

72.19

81.18

90.17

95.40

14.96

R 1.00

7.19 TYP

FM-05986.AI4

Functional Description 4–1

4

Functional Description

This chapter describes the functional operation of the AlphaPC 164SX. The descrip­tion introduces the 21174 core logic chip and describes its implementation with the

2116 4PC microproce ssor , it s support ing memory, and I/O devices. Figure 1–1 s hows
the AlphaPC 164SX major functional components.

Bus timing and protocol information found in other data sheets and reference docu­mentation is not duplicated. See Appendix A for a list of supporting documents and
order numbers.

Note: For detailed descriptions of bus transactions, chip logic, and operation,

refer to the Alpha 21164PC Microprocessor Hardware Reference Man­ual and the 21174 Core Logic Chip Technical Reference Manual. For
details of the PCI interface, refer to the PCI System Design Guide.

4–2 Functional Description

AlphaPC 164SX Bcache Interface

4.1 AlphaPC 164SX Bcache Interface

The 21164PC microprocessor controls the board-level L2 backup cache (Bcache)

array (see Figure 4–1). The dat a bus ( data_h[1 27:0]) signals are sh are d with the sys­tem interface.

Figure 4–1 AlphaPC 164SX L2 Bcache Array

The Bcache is a 1MB , direct -mapped, pipelined , synchron ous burs t SRAM
(SSRAM) with a 128-b it data path . It is populated with a quantity of four

133-MHz, 64K × 32 SSRAM s for data stor e, and on e 133-MHz , 32K × 32
SSRAM for tag sto re. The Bca che supp orts 64-by te transfe rs to and from
memory.

data_ram_oe_h

21164PC

Microprocessor

Bcache

SRAM

index_h[21:4]

data_ram_we_h

tag_ram_oe_h

tag_ram_we_h

index_h[21:6]

tag_data_h[32:30],19

tag_data_h[29:20]
tag_data_par_h
tag_valid_h
tag_dirty_h
data_h[127:0]

st_clk

x

_h

idle_bc_h

fill_dirty_h

Tag

Array

Data

Array

21174

Functional Description 4–3

21174 Core Logic Chip

4.2 21174 Core Logic Chip

The 21174 core lo g i c c hi p pr o v id e s a cost-compe t it i ve s o lu t io n fo r d es i gn er s u s in g t h e
21164PC microprocessor to develop unipr oces sor syst ems. The chip provides a
128-bit memory interface and a PCI I/O interface, and i nclu des t he 21174-CA chip
packaged in a 474-pin p las ti c bal l gr id a rr ay (PBGA).

Figure 4–2 shows the AlphaPC 164SX implementation of the 21174 core logic chip.

Figure 4–2 Main Memory Interface

4.2.1 21174 Chip Overview

The 21 174 ap plication-specific int egrated circuit (ASIC) acc ept s add res se s and com­mands from the 21 164PC microproc essor and drive s the main memory array with the
address, contro l, and cloc k sign als. It also pro vid es an inte rfac e to the 64- bit PCI I/O
bus.

21164PC

data_h[127:0]

addr_h[39:4]
System Control

*

DIMM 0

DIMM 1
DIMM 2
DIMM 3

Quick

Switches

21174

Buffers

memadr_[13:0]

mem_dat[128:0]

bnmemadr[13:0]

memwe_l
memcas_l[7:0]
memrasb_l[7:0]

memrasa_l[7:0]
miscellaneous

bnmemwe_l
bnmemcas_l[7:0]
bnmemrasb_l[7:0]

bnmemrasa_l[7:0]
bnmiscellaneous

be_l[0:2]

64-Bit PCI

I/O Bus

addr_bus_req_h
addr_cmd_par_h
cack_h
cmd_h[3:0]
dack_h
fill_h
fill_dirty_h
fill_error_h
fill_id_h
idle_bc_h
int4_valid_h[3:0]
sys_reset_l
tag_dirty_h
victim_pending_h

*

4–4 Functional Description

21174 Core Logic Chip

The 21174 chip provides the following functions:

• Serves as the interface between the 21164PC microprocessor, main memory

(addressing and control), and the PCI bus. A three-entry CPU instruction queue
is implemented to capture commands should the memory or I/O port be busy.

• Provides control to the Quick Switch chips to isolate the L2 cache from the main

memory bus during private reads and writes.

• Generates the clocks, row, and column addresses for the SDRAM DIMMs, as

well as all of the memory control signals (RAS, CAS, WE). All of the required
SDRAM refresh control is contained in the 21174.

• Provides all the logic to map 21164PC noncacheable addresses to PCI address

space, as well as all the translation logic to map P CI DMA add resses to system
memory.

Two DMA conversion methods are supported:

• Direct mapping, in which a base offset is concatenated with the PCI address.

• Scatter-gather mapping, which maps an 8KB PCI page to any 8KB memory

page. The 21174 contains an eight-entry scatter-gather translation lookaside
buffer (TLB) , wh ere each entry holds f our c onse cut ive page table ent ri es (PTEs).

4.2.2 Main Memory Interface

Quic k Sw it che s p rov id e t he i nt er fac e be tw een th e 21164PC/L2 cac he (data_h[127:0])
and the memory/21174 (mem_data_h[127:0 ]). The AlphaPC 164SX supports four
168-pin unbuf fered 72-bit or 64-bi t SDRAM DIMM modules. Even parity i s generated
on the PCI bus.

The AlphaPC 164SX supports a maximum of 512MB of mai n memory. The memory

is organize d as two banks. Table 1–1 lists total memory option s al ong with the corre­sponding DIMM sizes r equired. All CPU c acheab le memory acce sses and PCI DMA
accesses are controlled and routed to main memory by the 21174 core logic chip.

The AlphaPC 164SX implements the alternate memory mode for SDRAM RAS
and CAS control signals. Alternate memory mode is explained in the 21174 Core
Logic Chip Technical Reference Manual.

Functional Description 4–5

21174 Core Logic Chip

4.2.3 PCI Devices

The AlphaPC 164SX uses the PCI bus as t he main I/ O bus for the majorit y of per iph-

eral functions. As Figure 4–3 shows, the board implements the ISA bus as an expan­sion bus for system support functions and for relatively slow peripheral devices.

Figure 4–3 AlphaPC 164SX PCI Bus Devices

The PCI bus supports multiplexed, burst mode, read and w rite transfers. It sup­ports synchronous operation of 33 MHz. It also supports either a 32 -bit or 64-bit
data path with 32-bit device support in the 64-bit configuration. Depending upo n
the configuration and operating frequencies, the PCI bus supports up to 264-MB/s
(33 MHz, 64-bit) peak throughput. The PCI p rovides parity on address and data
cycles. Three physical address spaces are supported:

• 32-bit memory space

• 32-bit I/O space

• 256-byte-per-agent configuration space

2117 4

CY82C693U-NC

Primary

J6

Secondary

J5

ISA EIDE

PCI

Slot 0

J19

PCI

Slot 1

J18

PCI

Slot 2

J17

PCI

Slot 3

J15

PCI

ISA Bus

Device IDSEL Select

Slot 2 16
Slot 0 17
Slot 1 18
PCI/ISA Bridge 19
Slot 3 20

4–6 Functional Description

ISA Bus Devices

The bridge from the 21164PC system bus to the 64-bit PCI bus is provided by the
21174 chip. It generates the required 32-bit PCI address for 21164PC I/O accesses
directed to the PCI. It also accepts 64-bit double address cycles and 32-bit single address
cycles. However, the 64-bit address support is subject to some constraints.

4.2.4 PCI/ISA Bridge Chip

The CY82C693U-NC chip provides the bridge between the PCI and the ISA bus,
and between the PCI and the EIDE bus. It also incorporates the logic for the follow­ing:

• Keyboard/mouse controller – An 8042-compatible interface is brought out to

separate 6-pin DIN connectors (J4).

• Real-time clock – A DS1287-compatible clock is backed up by a replaceable

battery (XB1).

• A PCI interface (master and slave).

• An ISA interface (master and slave).

• PCI and ISA arbitration.

Refer to the Cypress document CY82C693U hyperCache/Stand-Alone PCI
Peripheral Controller with USB Data Sheet for additional information.

4.2.5 PCI Expansion Slots

Four dedicated PCI expansion slots are provided on the AlphaPC 164SX. This
allows the system user to add addit ional 32-bit or 64-bit PCI options. Whil e both the
32-bit and the 64-bit slots use the standard 5-V PCI connector and pinout, +3.3 V is
supplied for those boards that require it. The CY82C693U-NC chip provides the
interface to the ISA expansion I/O bus.

4.3 ISA Bus Devices

Figure 4–4 shows the AlphaPC 164SX ISA bus implementation with peripheral
devices and connectors. Two dedicated ISA expansion slots are provided. System
support features such as serial lines, parallel port, and diskette controller are embed­ded on the module by means of an FDC37C669 combination controller chip.

Functional Description 4–7

ISA Bus Devices

4.3.1 Combination Controller Chip

The AlphaPC 164SX uses the Standard Microsystems Corporation FDC37C669

combination controller chip (see Figure 4–4). It is packaged in a 100-pin QFP con­figuration. The chip provides the following ISA peripheral functions:

• Diskette controller – Software compatible to the Intel N82077 FDC. Inte-

grates the fu n ctio n s o f the f or mat te r/ co nt roll er, digita l d ata se p ar at or, write
precompen sa ti on , an d da ta -ra te sele ct io n l ogic re qu irin g no ex te rn al filte r
components. Supports the 2.88-MB drive format and other standard diskette
drives used with 5.25-inch and 3.5-inch media. FDC data and control lines are
brought out to a sta ndard 34-pin connector (J1 1). A ribbon cable in terfaces the
connector to one or two diskette drives.

• Serial ports – Two UARTs with full modem control, compatible with NS16450

or PC16550 devices, are brought out to two separate onboard, 9-pin
D-subminiature connectors (J3).

• Parallel port – The bidirectional parallel port is brought out to an onboard

25-pin connector (J13). It can be brought out through a 25-pin female
D-subminiature connector on the bulkhead of a standard PC enclosure.

An onboard clock generator chip supplies a 14.3-MHz reference clock for the dis­kette data separator and serial ports.

4–8 Functional Description

ISA Bus Devices

Figure 4–4 AlphaPC 164SX ISA Bus Devices

4.3.2 ISA Expansion Slots

Two ISA expansion slots are provided for plug-in ISA peripherals (J22 and J23).

4.3.3 ISA I/O Address Map

Table 4–1 lists the AlphaPC 164SX ISA I/O space address mapping.

Table 4–1 ISA I/O Address Map

(Sheet 1 of 2)

Range (hex) Usage

000-00F 8237 DMA #1
020-021 8259 PIC #1
040-043 8253 timer
060-061 Ubus IRQ12 and NMI control

sd[7:0]

PCI-to-ISA

Bridge

CY82C693U-NC

la[23:17]

PCI

sd[15:0]

Combination

Controller

37C669

Diskette

Parallel

COM1/2

ISA0

ISA1

sa[19:0]

sa[15:0]

Transceivers

EIDE – Primary

EIDE – Sec ondary

Functional Description 4–9

Interrupts

4.3.4 Flash ROM Address Map

After reset, the flash ROM is set to location 0. The 21174 supports cache fills and
uncacheable reads from the flash ROM (that is, the 21174 does multiple reads to the
flash ROM to assemble full octawords). The 21164PC can start executing directly
from the flash ROM.

Once the boot code that was stored in the flash ROM has been executed, and mem­ory has been initialized, the flash ROM is mapped to locations

87.C000.000–87.FFFF.FFFF.

4.4 Interrupts

Interrupts and general-purpose inputs are acquired by the 21174 through a free­running 32-bit external shift register. The int_sr_ load_l s ignal is asse rted low to load
the interrupts into the shift register. The int_clk signal clocks the shift register con­tents into the 21174 through the int_sr_in pin. The shift register operates continu­ously at a rate of ¼ the chipset clock rate .

The state of each interrupt can be read through the interrupt request register. Note
that the state of the interrupts will pers ist in the interrupt request register fo r up to
3 µs after t he interrupt has been deasserted a t the shift re gister. If the interrupt bit in
the interrupt request register is not promptly cleared, a second interrupt might be
taken before the shift register scans the deasserted value into the interrupt request

070 CMOS RAM address and NMI mask register
080-08F DMA page registers
0A0-0A1 8259 PIC #2
0C0-0DF 8237 DMA #2
2F8-2FF Serial port—COM2

370-377 Secondary diskette (floppy)
3BC-3BF Parallel port—LPT1
3F0-3F7 Primary diskette (floppy)
3F8-3FF Serial port—COM1

Table 4–1 ISA I/O Address Map

(Sheet 2 of 2)

Range (hex) Usage

4–10 Functional Description

Interrupts

register. Interrupts latched in the interrupt request register can be reset individually
by writing a 1 to the bit to be cleared. This immediately cl ear s the bit to avoi d taking

a second interrupt. Figure 4–5 shows the interrupt request register.

Figure 4–5 Interrupt Request Register

The interrupt mask register provides individual mask bits for each interrupt.

Table 4–2 lists the AlphaPC 164SX system interrupts, and Table 4–3 lists the ISA
interrupts.

1

IPL = interrupt priority level (fixed)

Table 4–2 AlphaPC 164SX System Interrupts

21164PC Interrupt IPL

1

Suggested Usage AlphaPC 164SX Usage

cpu_irq[0] 20 Corrected system error Reserved
cpu_irq[1] 21 — PCI and ISA interrupts
cpu_irq[2] 22 Interprocessor and

timer interrupts

TOY clock interrupt

cpu_irq[3] 23 — Reserved
pwr_fail_irq 30 Powerfail interrupt Reserved
sys_mch_chk_irq 31 System machine check

interrupt

NMI and 21174 errors

mch_hlt_irq — Halt Reserved

31 24 23 20 19 16 15 12 11 08 07 06 05 03 02 01 00

63 62

A2 A3A1A0B2 B3B1B0

C2 C3C1C0D2 D3D1D0

06 07050402 030100

Reserved
NMI INT
Halt INT
Reserved
Real-time CLK_INT
ISA_INT
PCI_INT A

n

PCI_INT B

n

PCI_INT C

n

PCI_INT D

n

CONFIG[7:0]

Reserved
21174 CLK_INT
ERROR INT

61 32

Functional Description 4–11

Interrupts

1

The # symbol indicates an active low signal.

Table 4–3 ISA Interrupts

Interrupt
Number Interrupt Source

IRQ0 Internal timer
IRQ1 Keyboard
IRQ2 Interrupt from controller 2
IRQ3 COM2
IRQ4 COM1
IRQ5 Available
IRQ6 Diskette (floppy)
IRQ7 Parallel port
IRQ8#

1

Reserved
IRQ9 Available
IRQ10 USB
IRQ11 Available
IRQ12 Mouse
IRQ13 Available
IRQ14 EIDE
IRQ15 EIDE

4–12 Functional Description

System Clocks

4.5 System Clocks

Figure 4–6 shows the AlphaPC 164SX clock generation and distribution scheme.
The AlphaPC 164SX system includes input clocks to the microprocessor as well as

clock distribution for the various system memory and I/O devices. There are other
miscellaneous clocks for ISA bus support. System clocking can be divided into the
following three main areas:

• Microproc essor inp ut clock — The input clock r uns at the operating fr equency

of the 21 16 4PC microp rocess or. The AlphaPC 164SX supports c ycle time s from

2.50 ns to 1.88 ns. This implies input clock frequencies from 400 MHz to
533 MHz. The clock is provid ed by using a s ynthesize r. The synthesizer’s o utput
is used as the input clock for the 21164PC.

• Clock distribution — Clock dist ri bution includes the dist rib ution of system

clocks from the 21164PC microprocessor to t he sys tem l ogic. The AlphaPC
164SX clock distribution scheme is flex ible enoug h to allow t he majo rity of c ycle­time combinations to be supported. Because the PCI is synchr onous to t he system
clock generated by the 21164PC microprocessor, the PCI cyc le t ime i s a mul ti ple
of th e 21164PC cycle time. This distribution scheme supports a PCI operation of
33 MHz.

• Miscella neous clocks — The miscellaneous clocks include those needed for

ISA and the co mbinati on cont roll er. These clocks are pr ovide d by a cryst al a nd a
frequency generator with fixed scaling.

Functional Description 4–13

System Clocks

Figure 4–6 AlphaPC 164SX System Clocks

At system reset, t he cl ock syn thesi zer i s prog rammed to pr ovide a 400-MHz c lock t o
the 211 64PC

. The IRQ pins in the 21164PC are either pulled up or down to set the

internal driver to divide by 6, providing a system clock of 66 MHz (sys_clk_out1).
If an operating frequency other than 400 MHz is selected by the configuration

switches, the boot code changes the synthesizer output; the 21174 drives the correct
divide ratio onto the IRQ lines and resets the CPU. If an invalid speed setting is
selected, the system defaults to the operating speed of 400 MHz.

DIMM0

Microprocessor

Clock

Synthesizer

21164PC

Microprocessor

PCI

Slots

ISA

Slots

dram_clkax2
dram_clkbx2

dram_clkcx2
dram_clkdx2

pciclk_slot0
pciclk_slot1
pciclk_slot2
pciclk_slot3

14mhz_out

osc

sysclk

pciclk_sio

clk_in_l

clk_in_h

irq_h[3:0]

CY2308

PLL

DIMM1

DIMM2

DIMM3

21174

Bridge

14.3-MHz
Oscillator

37C669

Comb.

Controller

Page

Boundary

PAL

cyb_pal_clk

4–14 Functional Description

Reset and Initialization

The 21 164PC microproce ssor produces the divided c lock output sign al sys _clk_out1
that drives the CY2308 PLL clo ck- dr iver chip. This clock provides the references to
synchronize the 21164PC microprocessor and the 21174 chip. The 21174 provides
the system memory and I/O (PCI) clock references. It also provides system-level
clocking to DIMMs, PCI slots, the PCI-ISA bridge, the PCI ID control ler, and the
PCI arbiter.

A 14.3-MHz crystal produces the signal 14mhz_out. This signal is delivered to the
FDC37C669 combination controller for the diskette data separator and other I/O
clocks. The combination controller produces output clock osc, which is then deliv­ered to the two ISA slots and the PCI-to-ISA bridge for synchronization.

4.6 Reset and Initialization

A TL7702B power monitor senses the +3.3-V rail to ensure that it is stable before
+2.5 V is applied to the 21164PC. In normal operation, if the +3.3-V rails fall below
+2.5 V, the power monitor enables shdn_l, which turns off the +2.5-V regulator.

An external reset switch can be connected to J20. The reset function initializes the
21164PC and the system logic. The p_dcok signal provides a full system initializa­tion, equivalent to a power-down and power-up cycle.

In addition, the fan sense signal (fan_ok_l) is logically ORed with the reset switch
output and the p_dcok signal. This signal (monitor_reset_l) is used to reset the
MAX708R +3.3-V monitor. If any of the signa ls be come ass erted , or if +3.3 V d rops
to +2.5 V, then dc_ok_h is deasserted, which causes a system reset.

Figure 4–7 shows the logic controlling system reset and initialization.

Figure 4–7 System Reset and Initialization

2

3

4

8

Sense

shdn_l

To +2.5-V Regulator

Debounce

J2

J14

J20

J2

Reset
Switch

fan_ok_l

p_dcok

3-V

Monitor

dc_ok_h

PCI-ISA

Bridge

21174

cpu_reset

21164PC

+3.3 V

Fan
Sensor

Power
Supply

Functional Description 4–15

DC Power Distribution

4.7 DC Power Distribution

The AlphaPC 164SX derives its system power from a user-supplied PC power sup­ply. The power supply must provide +12 V dc and −12 V dc, −5 V dc, +3 V dc, and
+5 V dc (Vdd). The dc power is supplied through power connector J2 , as shown in

Figure 4–8. Power is distributed to the board logic through dedicated power planes
within the six-layer board structure.

Figure 4–8 shows that the +12 V dc, −12 V dc, and −5 V dc are supplied to ISA con­nectors J22 and J23. The +12 V dc and − 12 V dc a re su ppl ied to ISA connectors and
PCI32 connectors J15 and J17. The + 12 V dc is also s upplie d to the CPU fan co nnec ­tor J14, and auxiliary f an connector J16. Vdd (+5.0 V) is supplied to IS A connecto rs,
PCI32 connectors, and most of the board’s integrated circuits. Vdd also drives the
+2.5-V regulator, which supplies the 21164PC microprocessor.

Figure 4–8 AlphaPC 164SX Power Distribution

+12 V

−12 V
+5 V (Vdd)

−5 V

Gnd

+3.3 V

10
12

4, 6,
19, 20

18

1, 2, 11

3,5,7,13,
15,16,17

ISA Conn.

PCI32
Conn.

Spkr

Conn.

Integrated

Circuits/Clocks

Fan

CPU

Fan

21164PC

+2.5-V

Regulator

+3.3-V Pull-Ups

Pull-Downs

+5-V

Pull-Ups

Power Connector J2

PCI64
Conn.

4–16 Functional Description

Serial ROM and Debug Port Support

4.8 Serial ROM and Debug Port Support

Though it is not needed for normal operation, there is logic support for the use of a
serial ROM and debug port. If an SROM is populated, the 21164PC loads its boot
code from the SROM instead of from flash ROM. This code initializes the system,
then transfers control to either the Mini-Debugger or the selected firmware, depend­ing upon the setting of the configuration jumper.

Upgrading the AlphaPC 164SX 5–1

5

Upgrading the AlphaPC 164SX

For higher system speed or greater throughput, SDRAM memory can be upgraded
by replacing DIMMs with those of greater size.

When configuring or upgrading SDRAM, observe the following rules:

• Each DIMM must be a 168- bi t unbuffered vers ion and have a frequency of

100 MHz.

• Each bank consists of two DIMMs and must be fully populated.

• Both DIMMs in the same bank must be of equal size.

5.1 Configuring SDRAM Memory

Although not an exhaus tive list, Table 5–1 lists the tested SDRAM memory
configurations ava ilable. As additiona l configurati ons become available, the y will be
posted in online revisions of this manual on the Alpha OEM World Wide Web
Internet site. See Appendix A for the URL.

For a list of vendors who supply components and accessories for the
AlphaPC 164SX, see Appendix A.

Refer to Fig ure 2–1 for DIMM connector locations.

Note: 1Mb × 72 and 1Mb × 64 DIMMs are not supported.

5–2 Upgrading the AlphaPC 164SX

Upgrading SDRAM Memory

5.2 Upgrading SDRAM Memory

You can upgrade memory in the AlphaPC 164SX by adding more DIMMs or

replacing the ones you have with a greater size. Refer to Figure 2–1 for DIMM
connector locations.

Use the following general guidelines:

1. Observe antistatic precautions. Handle DIMMs only at the edges to prevent
damage.

2. Remove power from the system.

1

64-bit-wide DIMMs can also be used.

Table 5–1 AlphaPC 164SX SDRAM Memory Configurations

Bank 0

1

Bank 1

1

Total Memory J7 J8 J9 J10

32MB 2Mb × 72 2Mb × 72 ——

64MB 2Mb

× 72 2Mb × 72 2Mb × 72 2Mb × 72

4Mb

× 72 4M b × 72 ——

96MB 4Mb

× 72 4Mb × 72 2Mb × 72 2Mb × 72

128MB 4Mb

× 72 4Mb × 72 4Mb × 72 4Mb × 72

8Mb

× 72 8M b × 72 ——

160MB 8Mb

× 72 8M b × 72 2Mb × 72 2Mb × 72

192MB 8Mb

× 72 8M b × 72 4Mb × 72 4Mb × 72

256MB 8Mb

× 72 8Mb × 72 8Mb × 72 8Mb × 72

16Mb

× 72 16Mb × 72 ——

512MB 16Mb

× 72 16Mb × 72 16Mb × 72 16Mb × 72

Upgrading the AlphaPC 164SX 5–3

Increasing Microprocessor Speed

3. Align the DIMM so that the notch in the DIMM matches the key in the socket.

4. Firmly p ush the DIM M straight into the connector. Ensure that the DIMM snaps
into the plastic locking levers on both ends.

5. Restore power to the system.

5.3 Increasing Microprocessor Speed

This section describes how to complete the following actions to increase
microprocessor speed:

• Replace the Alpha 21 16 4PC micropr ocessor with an Al pha chip that ha s a hig her

speed rating.

• Reconfigure the clock divisor switches.

5.3.1 Preparatory Information

Caution: Static-Sensitive Component – Due to the sensitive nature of electronic

components to static electricity, anyone handling the microprocessor
must wear a properly grounded antistatic wriststrap. Use of antistatic
mats, ESD approved workstations, or exercising other good ESD prac­tices is recommended.

An Alpha 21 164PC microproc essor with a hig her speed ratin g is available fr om your
local distributor. See Appendix A for information about supporting products.

When replacing the microprocessor chip, also replace the thermal conducting
GRAFOIL pad. See Appendix A for information about the parts kit, which includes
the heat sink, GRAFOIL pad, two hex nuts, heat-sink clips, 52-mm fan, and four
screws.

5.3.2 Required Tools

The following tools are required when replacing the microprocessor chip:
A TS30 manual nut/torque driver (or equivalent) with the following attachments is

required to affix the heat sink and fan to the microprocessor’s IPGA package:

• 1/4-inch hex bit

• 3/8-inch socket with 1/4-inch hex drive

• #2 Phillips-head screwdriver bit

5–4 Upgrading the AlphaPC 164SX

Increasing Microprocessor Speed

5.3.3 Removing the 21164PC Microprocessor

Remove the microprocessor currently in place at location U31 by performing the
following steps:

1. Unplug the fan power/sensor cable from connector J14 (see Figure 2–1).

2. Remove the four 6–32 × 0.625-inch screws that secure the fan to the heat sink.

3. Remove th e fan.

4. If the sink/ chip/fa n clip is us ed, remove it by unhoo king its end s from around t he
ZIF socket retainers.

5. Using a 3/8-in ch so cket, re move the two nu ts secu ring th e heat si nk to the micro­processor studs.

6. Remove the heat sink by gently lifting it off the microprocessor.

7. Remove and discard the GRAFOIL heat conduction pad.

8. Thoroughly clean the bottom surface of the heat sink before affixing it to the
new microprocessor.

9. Lift the ZIF socket actuator handle to a full 90° angle.

10. Remove the microprocessor chip by lifting it straight out of the socket.

5.3.4 Installing the 21164PC Microprocessor

Install the new microprocessor in location U31 by performing the following steps:

Note: Install the heat sin k only after the mi cro proces sor ha s be en ass embled t o

the ZIF socket.

1. Observe antistatic precautions.

2. Lift the ZIF socket actuator handle to a full 90° angle.

3. Ensure that all the pins on the microprocessor package are straight.

4. The ZIF socket and microprocessor are keyed to allow for proper installation.
Align the microprocessor, with its missing AD01 pin, with the corresponding
plugged AD01 position on the ZIF socket. Gently lower into position.

5. Close the ZIF socket actuator handle to its locked position.

6. Install the heat sink and heat-sink fan as directed in the following steps. A heat­sink/fan kit is available from the vendor listed in Appendix A. Refer to
Figure 5–1 for heat-sink and fan assembly details.

Upgrading the AlphaPC 164SX 5–5

Increasing Microprocessor Speed

Figure 5–1 Fan/Heat-Sink Assembly

a. Put the GRAFOIL thermal pad in place. The GRAFOIL pad is used to

improve the thermal conductivity between the chip package and the heat
sink by replacing micro air pockets with a less insulative material. Perform
the following steps to position the GRAFOIL pad:

1. Perform a visual inspection of the package slug to ensure that it is free of
contamination.

2. Wearing clean gloves, pick up the GRAFOIL pad. Do not perform this
with bare hands because skin oils can be transferred to the pad.

3. Place the GRAFOIL pad on the gold-plated slug surface and align it with
the threaded studs.

Screw, 6–32 × 0.625 in
Qty 4
Torque to 3

±1 in-lb

Fan

Clip, Heat-Sink/Chip/Fan

Nut, Hex,
Aluminum
Flats, Qty 2
Torque to15

±2 in-lb

Heat Sink, with Fan
Mounting Holes

Thermal Pad

Alpha 21164PC

Airflow

5–6 Upgrading the AlphaPC 164SX

Increasing Microprocessor Speed

b. Attach the microprocessor heat sink. The heat-sink material is clear

anodized, hot-water -seal ed, 6061-T6 aluminum. The nut material is 201 1 -T3
aluminum (this grade is critical). Perform the following steps to attach the
heat sink:

1. Observe antistatic precautions.

2. Align the heat-sink holes with the threaded studs on the ceramic package.

3. Handle the heat sink by the edges and lower it onto the chip package,
taking care not to damage the stud threads.

4. Set a calibrated torque driver to 15 in -lb, ±2 in-lb, (2.3 Nm, ±0.2 Nm).
The torque driver should have a mounted 3/8-inch socket.

5. Insert a nut i nto the 3/8-inch sock et , pl ac e on one of the studs, and tighten
to the specified torque. Repeat for the second nut.

6. If the sink/chip/fan clip is used, properly install it by positioning it over
the assembly and hooking its ends around the ZIF socket retainers.

c. Attach the heat-sink fan assembly:

1. Place the fan assembly on top of the heat sink, aligning the fan mounting
holes with the corresponding threaded heat-sink holes. Align the fan so
that the fan power/sensor wires exit the fan closest to connector J14 (see
Figure 2–1). Fan airflow must be directed into the heat sink (fan label fac­ing down toward the heat sink).

2. Using a calibrated torque driver set to 3 in-lb, ±1 in-lb, secure the fan to
the heat sink with four 6–32 × 0.625-inch scre ws.

3. Plug the fan powe r/sensor cable into connector J14.

Note: When installing the microprocessor, you must change the frequency of

its clock output by setting the system clock divisor switches, as
described in Section 2.2.

Support, Products, and Documentation A–1

A

Support, Products, and Documen tation

A.1 Customer Support

The Alpha OEM website provides the following information for customer support.

URL Description

http://www.digital.com/alphaoem

Contains the following links:

• Developers’ Area: Development tools, code examples,

driver developers’ information, and technical white
papers

• Motherboard Products: Motherboard details and

performance information

• Microprocessor Products: Microprocessor details and

performance information

• News: Press releases

• Technical Information: Motherboard firmware and

drivers, hardware compatibility lists, and product
documentation lib rary

• Customer Support: Feedback form

Supporting Products

A–2 Support, Products, and Documentation

A.2 Supporting Products

This section lists sources for components and accessories that are not included with
the AlphaPC 164SX.

A.2.1 Memory

Dual inline memory modules ( DIMMs) are availabl e from a variety of vend ors. For a
list of the qualified vendors, visit the Alpha OEM World Wide Web Internet site at
URL:

http://www.digital.com/alphaoem

Click on

Tec hnical Inform ation .

Then click on

Alpha OEM Hardware Compatibility List.

A.2.2 Thermal Products

Components included in this heat-sink and fan solution are heat sink, GRAFOIL
pad, two hex nuts, heat-sink clips, 52-mm fan, and four screws. These are available
from:

United Machine and Tool Design Company, Inc.

18 River Road
P.O. Box 168
Fremont, NH 03044
Phone: [phone]
Fax: [phone]
PN 70-33148-01

A.2.3 Power Supply

An ATX form-factor power supply, suitable for use with the AlphaPC 164SX

(+3.3 V, +5 V, –5 V, +12 V, –12 V), is available from:

Quantum Power Labs, Inc.

1410 Gail Borden Place C-4
El Paso, TX 79935
Phone: [phone]
Fax: [phone]
PN AP2-5300FRV (300 W)

Alpha Products

Support, Products, and Documentation A–3

Antec, Inc.

2859 Bayview Drive
Fremont, CA 94538
Phone: [phone], ext. 313
PN PP-253V (250 W)

A.2.4 Enclosure

An enclosure, suitable for housing the AlphaPC 164SX and its power supply, is
available from:

Delta Axxion Technology

1550 Northwestern
El Paso, TX 79912
Phone: [phone]
PN DL17

A.3 Alpha Products

To order the AlphaPC 164SX motherboard, contact your sales office. The following
tables list some of the Alpha products available.

Note: The following products an d order number s might have be en revised . For

the latest versions, contact your local distributor.

Motherboard kits include the motherboard and motherboard user’s manual.

Chips Order Number

Alpha 21164PC microprocessor (400 MHz) 211PC-01
Alpha 21164PC microprocessor (533 MHz) 211PC-03

Motherboard Kits Order Number

AlphaPC 164SX Motherboard Kit for Windows NT 21A05-A0
AlphaPC 164SX Motherboard Kit for DIGITAL UNIX 21A05-A1

Alpha Documentation

A–4 Support, Products, and Documentation

Design kits include full documentation and schematics. They do not include related
hardware.

A.4 Alpha Documentation

The following ta bl e l ist s s ome of the available Alpha documentation. You can down­load Alpha documentation from the Alpha OEM World Wide Web Internet site:

http://www.digital.com/alphaoem

If you have feedback about the Alpha technical documentation, please send your
comments to

[e-mail].

1

To purchase the Alpha Architecture Reference Manual, contact your sales offic e or call

Butterworth-Heinemann (DIGITAL Press) at 1-800-366-2665.

Design Kits Order Number

AlphaPC 164SX Motherboard Software Developer’s Kit
(SDK) and Firmware Update

QR-21A04-12

Title Order Number

Alpha Architecture Reference Manual

1

EY–W938E–DP
Alpha Architecture Handbook EC–QD2KB–TE
Alpha 21164PC Microprocessor Hardware Reference Manual EC–R2W0A–TE
Alpha 21164PC Microprocessor Data Sheet EC–R2W1A–TE

Third–Party Documentation

Support, Products, and Documentation A–5

A.5 Third–Party Documentation

You can order the following third-party documentation directly from the vendor.

Title Vendor

PCI Local Bus Specification, Revision 2.1
PCI Multimedia Design Guide, Revision 1.0
PCI System Design Guide
PCI-to-PCI Bridge Architecture Specification,
Revision 1. 0
PCI BIOS Specification, Revision 2.1

PCI Special Interest Group
U.S. 1–800–433–5177

International 1–503–797–4207
Fax [phone]

CY82C693U hyperCache/Stand-Alone PCI
Peripheral Controller with USB Data Sheet

Cypress Semiconductor Corporation
3901 North First Street
San Jose, CA 95134
Phone: [phone]

Super I/O Floppy Disk Controller with Infrared
Support (FDC37C669) Data Sh eet

Standard Microsystems Corporation
80 Arkay Drive
Hauppauge, NY 11788
Phone: [phone]
Fax: [phone]

Index–1

Index

Numerics

21164 microprocessor. See Microprocessor.
21174 Core logic chip. See Core logic chip.
37C669. See Combination controller.

A

Abbreviations, x
Airflow requirements, 3-2
ATX hole specification, 3-3
ATX I/O shield requirements, 3-4

B

Bcache

interface, 4-2
subsystem, 1-4

Bit notation, xi
Block diagram, 1-2

C

CAS, 4-4
Clocks, 1-5

14.3-MHz reference, 4-7

Combination controller, 1-4, 4-6, 4-7
Communication ports, 4-7
Component list, 2-3

Components and features, 1-1
Connectors, 2-3

pinouts, 2-6 to 2-14

Conventions

numbering, xii

Core logic chip, ?? to 4-4
CPU. See Microprocessor.
Current

dc ampere requirements, 3-1

D

Data field size, xi
Data units, xi
DC power requirements, 3-1
Debug monitor

system support, 1-5

Design support, 1-6
DIGITAL UNIX

SDK support, 1-6
SRM console firmware, 1-6

Dimensions

motherboard, 3-2

Direct mapping, 4-4
Diskette controller, 4- 7
DMA conversion, 4-4

Index–2

E

Environmental requirements, 3-2
Extents and ranges, xii

F

FDC37C669. See Combination controller.
Flash ROM

AlphaBIOS firmware, 1-5

I

I/O shield dimensions, 3-4
Interface

main memory, 4-4

Interrupts, 4-9

system assignment, 4-10

INTnn, xi
ISA

bus, 4-5
devices, 4-6
expansion slots, 4-6
interface, 1-4

J

Jumpers

Bcache size, 2-5

K

Keyboard

controller, 4-6

M

Mapping

direct (DMA), 4-4
scatter-gather, 4-4

Memory

alternate mode, 4-4
main, 4-4
SDRAM DIMM pinouts, 2-9
subsystem, 1-3

Microprocessor

speeds, 1-1
upgrading, 5-1 to 5-6

Motherboard

ATX hole specification, 3-3
ATX I/O shield, 3-4
componen t descriptions, 2-3
dimensions, 3-2

Mouse

controller, 4-6

N

Numbering convention, xii

O

Operating systems

software support, 1-5

Ordering products and documentation, A-3

P

Packaging

21174 chip, 4-3

Parallel port, 4-7
PCI

21174 role, 4-6
bus, 4-5
bus speed, 4-5
device implementation, 4-5
expansion slots, 4-6
interface, 1-4

Pinouts

connectors, 2-6 to 2-14

Power

distribution, 4-15
requirements, 3-1

Index–3

Power supply

dc ampere requirements, 3-1
wattage requirements, 3-1

Processor. See Microprocessor.
PTE, 4-4

R

Ranges and extents, xii
RAS, 4-4
Reset, 4-14
RO

definition, x

RW

definition, x

S

Scatter-gather

mapping, 4-4

SDK, 1-5 to 1-6
Serial ports, 4-7
Serial ROM. See SROM.
Shield dimensions

I/O, 3-4

Software suppor t, 1-5
SRM Console, 1-6
SROM, 4-16
Support

technical, A-1

System

components and features, 1-1
software support, 1-5

T

Time-of-year clock, 4-6
TLB, 4-4

U

UARTs, 4-7
UNDEFINED

definition, xiii

UNIX. See DIGITAL UNIX.
UNPREDICTABLE

definition, xiii

Upgrading

microprocessor, 5-3

W

Windows NT

AlphaBIOS firmware, 1-5
SDK support, 1-6

WO

definition, x