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

Introduction to SPI
SPI Programming Manual—427506-006
1-10
The Environment for D-Series RVUs
The extended SPI interface is based on and assumes an understanding of the features
of the basic SPI interface described in this manual.
The Environment for D-Series RVUs
For D-series RVUs, the features of the NonStop operating system prompted several
changes relevant to management applications. The operating system incorporates
numerous changes intended to improve CPU utilization and allow larger I/O
configurations. In part, these improvements were brought about by raising the limits on
a number of system parameters to allow:
•
More concurrent processes per CPU
•
More I/O devices per node
•
More I/O subdevices per device
•
More opens (concurrent access paths) per device and subdevice
•
More pending operations (outstanding messages)
These changes require the introduction of new and expanded data structures,
including:
•
New process identifiers
•
A new file name format
•
New SPI and EMS tokens corresponding to these new data structures
These structures are supported by a set of system procedures and associated error
numbers and error lists.
Implications for Management Applications
In general, an application on a node running a C-series RVU runs without modification
at a low PIN on a node running a D-series RVU. In particular, if all the processes
involved are running at low PINs, management applications currently on a node
running a C-series RVU should run identically on a node running a D-series RVU, or
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.
The SCP process performs some
reconciliation of incompatibilities
between different versions of the
extended interface.
Manual
SPI Programming Manual SPI Common Extensions Manual
Table 1-1. Comparison: SPI Basic and Extended Features (page2of2)
Basic SPI Extended SPI