Xcell Journal Issue 78: Charge to Market with Xilinx 7 Series ...

XCELLENCE IN AUTOMOTIVE APPLICATIONS
that case, it is possible to configure
only a minimalist subsystem at
power-up (that is, the bootloader and
the portion of the system application
immediately required) and keep the
rest of the system idle until it is necessary
to initialize it. Splitting this
startup activity into two phases
speeds up the initialization process
in case the system needs a fast
response at power-up or upon waking.
For this purpose, the system
architecture is decomposed into a
static region and one or more partially
reconfigurable regions (PRRs).
The static region encompasses the
system responsible for carrying out the
startup process, typically the host
CPU, along with the reconfiguration
engine and a data link to the bitstream
repository. The other regions are
described by specific partial bitstreams
that can be downloaded later,
when the application needs them.
Also, if PRR regions are disabled, then
it is possible to reduce the power consumption
of the device proportionally to
the portion of area that is not in use.
Power-saving modes are especially relevant
in automotive battery-powered
ECUs. For this reason, automotive MCUs
make use of low-power modes to keep
TWO CRUCIAL STANDARDS
The automotive industry is already designing electronics
with two crucial standards in mind:
AUTOSAR, for handling embedded-system complexity
by means of appropriate software and hardware
architectures, and the upcoming ISO 26262, which governs
functional safety. Relevant technical concerns adopted
from ISO 26262 and released in AUTOSAR include the
detection and handling of safety issues like hardware
faults at runtime; abnormal timing and the broken logical
order of execution of applications; and data corruption,
among others.
INSIDE AUTOSAR
In recent years, electronic components have displaced
mechanical and hydraulic systems within vehicles. The
incursions continue, as designers begin to implement
additional control, monitoring and diagnostic functions in
software. In fact, electronics technology makes it possible
to deliver new functions whose development would be
costly or not feasible if using only mechanical and
hydraulic solutions. These parts must meet stringent safety
requirements to avoid faulty states and failures.
While software-related product failures have so far
been relatively rare, continued growth in the use of software
as part of manufactured products increases the system
complexity and, together with shorter product development
cycles, leads in the end to product failures. The
automotive industry has attacked this problem by forming
coalitions and enacting standards to ensure the application
and creation of safe and reliable software.
The Motor Industry Software Reliability Association
(MISRA), for example, is a consortium of vehicle manufacturers
such as Ford and Jaguar Land Rover, component
suppliers and engineering consultancies. By defining a
the ECU power consumption to a minimum
when the vehicle is inactive (that
is, in sleep mode). Analogously, the use
of blank bitstreams to disable portions
of the FPGA when not required reduces
logic activity and consequently, dynamic
power consumption.
Automotive designers can also use a
technique inherited from aerospace
applications in systems based on runtime
reconfigurable logic. Configuration
scrubbing can recover the system from
failures on SRAM resources originated
by SEU or electromagnetic interference.
Periodically reconfiguring the
hardware peripherals guarantees that
series of software programming rules, MISRA seeks to promote
best practices in developing safety-related electronic
systems in road vehicles and other embedded systems.
The Automotive Open System Architecture, or
AUTOSAR, is a partnership of automotive manufacturers,
suppliers and other companies from the electronics, semiconductor
and software industries working together to
develop a de facto open industry standard for automotive
electrical/electronic (E/E) architectures, targeting several
major issues. These include managing the growing complexity
of automotive E/E systems associated with the continuous
increase of functionality; improving flexibility for product
modification, upgrade and update; improving scalability
of solutions within and across product lines; improving the
quality and reliability of E/E systems; and enabling the
detection of errors in early design phases.
This initiative faces the challenge of having to integrate a
growing amount of software and electronic technologies
across a vast ecosystem of suppliers. By simplifying the
exchange and update options for software and hardware, the
AUTOSAR approach forms the basis for reliably controlling the
rising complexity of the E/E systems in motor vehicles, as well
as improving cost-efficiency without compromising quality.
The AUTOSAR initiative, founded in 2003, is a natural evolution
of the older OSEK/VDX consortium—born one decade
before and spearheaded by some German and French
automakers—but now with more ambitious goals and extended
to most of the automotive OEMs all over the world.
The core partners of AUTOSAR are the BMW Group,
Bosch, Continental, Daimler, Ford, General Motors, PSA
Peugeot Citroën, Toyota and the Volkswagen Group. In addition
to these companies, more than 160 other members play
an important role in the success of the partnership. Thus,
under the slogan “cooperate on standards, compete on
28 Xcell Journal First Quarter 2012