SPI Common Extensions Manual

Introduction to SPI Extensions
SPI Common Extensions Manual—427508-001
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Overview of Extended SPI
6. An application (or user) can respond to event-generating situations according to
requirements you provided. In this case, your application could stop sending
requests to the subsystem.
Overview of Extended SPI
This comparison shows some ways the extensions build on basic SPI:
Basic SPI Extended SPI
Procedures Provides procedures for creating
and decoding SPI messages.
Uses the basic SPI procedures.
Data
definitions
Defines basic message
structures and the data types on
which all tokens are based
(ZSPI).
Defines many additional tokens,
structures, error numbers, event
numbers, and other data items (ZCOM).
Commands Defines a single command:
GETVERSION.
Defines over 40 commands, and
specifies the contents of the command
and response messages.
Errors Defines the basic mechanism for
reporting errors, defines errors
returned by the SPI procedures,
and defines some common errors
returned in SPI responses.
Defines common errors reported by
subsystems under specific
circumstances and specifies the
contents of the associated error lists.
Events Provides the basic mechanism
for event messages (event
messages are one type of SPI
message).
Defines common events to be
generated by subsystems under
specific circumstances.
Object
names
Discusses object names in
general terms.
Makes specific recommendations for
naming objects, and provides specific
tokens for conveying object names in
messages.
Security Provides a basic buffer
checksum feature for detecting
corrupted messages.
Regulates command security based on
requester authorization and the
distinction between sensitive and
nonsensitive commands.
General
protocol
Defines basic message protocol
but leaves many implementation
decisions for the subsystem.
Standardizes many behaviors that basic
SPI leaves up to the subsystem.
Message
routing
Does not regulate message
routing.
Provides a message routing process
(SCP) that also provides security and
other features.
Compatibility Provides basic mechanisms for
determining versions of
requesters, servers, and the
definitions they use.
SCP performs some reconciliation of
incompatibilities between different
versions of the extended interface.
Manual
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