User`s guide

• Chapter 5, Board Requirements and Parameters, describes the board power

and environmental requirements, and identiﬁes major board components.

• Appendix A, System Register Descriptions, describes the control and status

registers of the DECchip 21071-CA and DECchip 21071-DA.

• Appendix B, SROM Initialization, describes the general SROM, Level 2

(L2) cache, and memory initialization steps and associated parameters.

It also includes information about the ﬁrmware interface, timing

considerations, SROM header, and conﬁguration jumpers.

• Appendix C, PCI Address Maps, provides the AlphaPC64 operating register

address space maps.

• Appendix D, Technical Support and Ordering Information, describes how

to obtain information and technical support, and how to order Digital

Semiconductor products and associated literature.

Document Conventions

This section describes the abbreviation and notation conventions used

throughout this guide.

Numbering

All numbers are decimal or hexadecimal unless otherwise speciﬁed. In cases

of ambiguity, a subscript indicates the radix of nondecimal numbers. For

example, 19 is decimal, but 19

and 19A are hexadecimal.

UNPREDICTABLE and UNDEFINED Deﬁnitions

Results speciﬁed as UNPREDICTABLE may vary from moment to moment,

implementation to implementation, and instruction to instruction within

implementations. Software can never depend on results speciﬁed as

UNPREDICTABLE.

Operations speciﬁed as UNDEFINED may vary from moment to moment,

implementation to implementation, and instruction to instruction within

implementations. The operation may vary from nothing to stopping system

operation. UNDEFINED operations must not cause the processor to hang, that

is, reach a state from which there is no transition to a normal state where the

machine can execute instructions.

Note the distinction between results and operations. Nonprivileged software

cannot invoke UNDEFINED operations.

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