SPI Programming Manual (G06.24+, H06.03+, J06.03+)

Introduction to SPI
SPI Programming Manual—427506-006
1-9
A Basic Interface and Extensions
A Basic Interface and Extensions
This manual describes the basic SPI interface. Many NonStop Kernel subsystems are
based on an extended version of SPI. These extensions, based on ZCOM data
definitions, and a common implementation of the extensions, based on ZCMK
definitions, are described in the SPI Common Extensions Manual .
Table 1-1. Comparison: SPI Basic and Extended Features (page1of2)
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 30 additional 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.
Using the basic SPI error reporting
mechanism, 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).
Using the basic SPI event reporting
mechanism, 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.
In addition to the checksum feature,
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.