Testing
and
Troubleshooting 3-17
Self-Tests and Diagnostics Overview
Three levels of overlapping diagnostics provide the primary service support tool for the computer.
These are the module self-tests, the self-test supervisory code,
and
the system diagnostics. The
module self-tests
and
self-test supervisory code are executed at powerup or
on
program request.
Some
module self-tests are executed individually at user request. The system diagnostics are
specific for each peripheral
in
the system
and
are run
on
request from the operator.
A power-up condition, a program request, or a command that simulates powerup causes the power
supply to generate a signal to the processor stack that puts the stack
in
self-test mode. When stack
self-test
is
completed, the stack signals
all
internal modules
on
the
110
interface to begin their
self-tests. The self-test supervisory code located
in
the loader
ROM
begins executing
its
tests when
the module self-tests are completed.
Module Self-Tests
The
first
level of diagnostics consists of the module self-tests. The module self-tests are low-level
tests which are initiated by computer modules
on
powerup or
on
hardware
or
software request. A
module
is
defined to be any section of the computer which
is
field
replaceable. Test results are
communicated to the user via LED indicators
on
the service panel. Each self-test
is
designed so that
its
results can
be
read by higher level diagnostics.
Each module's self-test
is
independent of the other self-tests. The failure of a module does not
cause the other modules to
fail
their self-tests except
in
the case of a power supply failure.
Self-Test Supervisory Code
The second level of diagnostics
is
the self-test supervisory code (STSC). The STSC
is
divided into
two parts. The
first
part
is
resident
in
the loader ROM
and
is
run as part of the power-up sequence.
The second part
is
resident
in
the power-up section of the operating system software.
The
STSC
in
the loader ROM reads the self-test results of the
110
cards which could
be
used in
loading the operating system
and
reports the results to the user.
It
also verifies the integrity of the
internal
110
bus. The STSC performs other tests
on
the system control module including RTC
and
NVM
checks.
The second part of the STSC salvages
"mapped
out"
RAM
blocks (16K bytes) which failed the
memory controller self-test.
It
also checks the non-loader
110
card self-test results.
System
Diagnostics
The third level of diagnostics
is
the system diagnostics. These diagnostics are programs written
in
high-level languages which can
do
further testing of the hardware system.
If
destructive testing
is
done (for example, disc writing), the user
is
warned of the effects of the testing before the test
is
run.
This code consists of two types of programs:
1)
verification programs for each peripheral
and
for a
minimum system of computer, terminal,
and
disc; 2) diagnostic program to diagnose problems
in
a
CS80
disc drive to a replaceable module.
These diagnostics are a part of the
HP-UX program
(in
directory CE.
II
til
it
i e
5)
and
are explained
in Chapter 5, Diagnostics, of the Series
500
HP-UX Section of the CE Handbook.