Military Embedded Systems Summer 2006

PC/104-Plus
with Pentium ® M
DIGITAL-LOGIC offers a large variety
of Embedded Computer in PC/104,
EPIC, EBX, smartModule and other
form factors.
MICROSPACE MSM855
behaves as expected is not the same as fully
testing the design. Some requirements may
lack tests, the requirements themselves
may be ambiguous or incomplete, and the
design may contain superfluous elements.
By using Simulink Verification and
Validation, coverage metrics can be
collected during simulation to indicate
untested design elements. The coverage
metrics are displayed directly in the
model using colored highlights and in a
dialog box with summary information.
Additionally, a detailed report of the coverage
analysis is created. The coverage
metrics collected include cyclomatic
complexity, decision coverage, condition
coverage, MC/DC, lookup table coverage,
and signal range coverage.
The MC/DC metric is essential for
DO-178B certification. It requires the
execution of each separate input to a
logical expression that can independently
affect the outcome of the decision while
other conditions are held constant.
Results of coverage analysis
Figure 5 shows the coverage analysis
for the right outer actuator recovery
logic in response to the execution of
23 requirements-based tests. Model
Figure 4
elements, highlighted in red, indicate
that full coverage of the design is
not achieved. By selecting transition
“[!RDL_act()|LIO_act()]” in the model,
the dialog box shown in the bottom lefthand
corner of the stateflow diagram
summarizes the coverage analysis: Full
decision coverage. Condition “LIO_
act()” was never true. Clicking on the
hyperlink in the dialog box displays the
detailed coverage report in the bottom of
Figure 5. Evaluating the MC/DC analysis
reveals that the right outer actuator never
transitioned into the Active mode because
the left outer actuator was in the Active
mode and the right inner actuator was
also in the Active mode, a scenario that
had not been set forth in the requirements.
Because this scenario was missing, a test
case had not been constructed. Additional
requirements are thus necessary to fully
describe the design.
In other design parts, coverage analysis
helped discover and remove redundant
design elements to simplify the design.
Ambiguous requirements were discovered
that resulted in an incorrect set of tests being
executed on the design. After assessing
all the design elements with incomplete
coverage, two additional requirements
were added, another two requirements
_ Intel ® Celeron ® M or Intel ®
Pentium ® M from 800MHz
up to 2.0GHz
_ 855GME 400MHz FSB, ICH4,
256-1024MB DDR-RAM
_ Extreme Graphic, 64MB,
DirectX 9 compatible, CRT
and DVO/LVDS
_ 6 x USB V2.0, LAN, AC97
SPD/if 5.1 sound stereo with
six-channel output and two
channel input
_ Passive and active cooling
concept
_ -25°C up to + 60°C
(operating temperature)
_ -40°C up to + 70°C (option)
For more Information:
www.digitallogic.com
Advanced Digital Logic Inc.
4411 Morena Blvd. Suite 101
San Diego, CA 92117-4328
Phone +1 858 490 0590
Fax +1 858 490 0599
sales@adlogic-pc104.com
www.adlogic-pc104.com
RSC# 39 @www.mil-embedded.com/rsc