792 IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. 58, NO. 3, MARCH 2011
Design and Verification of Hardware Building Blocks
for High-Speed and Fault-Tolerant
In-Vehicle Networks
Federico Baronti, Member, IEEE, Esa Petri, Student Member, IEEE, Sergio Saponara, Luca Fanucci, Member, IEEE,
Roberto Roncella, Member, IEEE, Roberto Saletti, Member, IEEE, Paolo D’Abramo, and Riccardo Serventi
Abstract—This paper presents the design, implementation, and
validation of a FlexRay transceiver and a SpaceWire (SpW) router
and interface, which constitute the main hardware building blocks
of the two in-vehicle communication standards. The FlexRay
protocol features data rates up to 10 Mb/s and time- and event-
triggered transmissions, along with scalable fault-tolerance sup-
port, and it is expected to become the standard network for
X-by-wire and active safety automotive systems. However, collision
avoidance and driver-assistance applications based on camera/
radar sensors require data rates up to hundreds of megabits per
second as well as fault tolerance, features that can hardly be
covered by current or expected automotive standards. In this sce-
nario, a promising technology seems to be the new SpW protocol,
currently used in avionics and aerospace.
Index Terms—Application-specified integrated circuit (ASIC),
automotive electronics, field-programmable gate array (FPGA),
FlexRay, high-speed communication, in-vehicle networks,
SpaceWire (SpW).
I. I NTRODUCTION
E
MERGING applications such as X-by-wire [1], [2] or vi-
sion subsystems for intelligent driver assistance and safety
warnings [3], [4] need in-vehicle networks with demanding
requirements in terms of high data rate, fault tolerance, and
deterministic message transmission. According to the Society
of Automotive Engineers, in-vehicle communication protocols
can be grouped in four classes bounded by the data transmission
speed [5], as shown in Fig. 1 together with the relevant appli-
cation domains. The Local Interconnect Network (LIN) and the
Controller Area Network (CAN) protocols are established as
the de-facto standards for A, B, and C classes, with data rates
from a few kilobits per second up to 1 Mb/s. Even though
not formally defined yet, networks over 1 Mb/s are grouped
Manuscript received June 23, 2008; revised March 14, 2009; accepted
June 30, 2009. Date of publication August 21, 2009; date of current ver-
sion February 11, 2011. This work was supported in part by the Ministero
dell’Istruzione, dell’Università e della Ricerca under Projects PRIN-2006 and
FIRB-RBIP06YLMY and in part by Regione Toscana under Project “Filiera
Idrogeno.”
F. Baronti, E. Petri, S. Saponara, L. Fanucci, R. Roncella, and R. Saletti are
with the Dipartimento di Ingegneria dell’Informazione: Elettronica, Informat-
ica, Telecomunicazioni, Università di Pisa, 56122 Pisa, Italy (e-mail: federico.
baronti@iet.unipi.it).
P. D’Abramo and R. Serventi are with the Automotive Business Unit,
Austriamicrosystems AG, 56023 Cascina, Italy (e-mail: paolo.dabramo@
austriamicrosystems.com).
Color versions of one or more of the figures in this paper are available online
at http://ieeexplore.ieee.org.
Digital Object Identifier 10.1109/TIE.2009.2029583
Fig. 1. Overview of the buses for in-vehicle networking.
in class D, targeting several applications, such as X-by-wire,
driver assistance and active safety based on high-bandwidth
devices, and infotainment. The research on fault-tolerant and
high-speed network implementation is still open [1]–[18].
The FlexRay standard is emerging as the reference solution
for X-by-wire applications [5]–[7]. FlexRay features data rates
up to 10 Mb/s, time- and event-triggered communication, and
scalable fault-tolerance support. However, advanced automo-
tive control systems for blind spot and lane departure warnings,
collision avoidance, and driver-assistance vision systems [3],
[4] rely on data coming from multiple high-bandwidth sensors
(radars, infrared, and charge-coupled device/CMOS cameras)
and hence require networks with data rates up to hundreds of
megabits per second. Existing high-speed automotive networks,
such as the Media Oriented System Transport (MOST) or the
IDB-1394 (automotive IEEE-1394), are not fault tolerant. They
are devoted to transport a large amount of data for infotain-
ment instead of safety or driver-assistance applications. This
challenging issue can be faced by introducing the SpaceWire
(SpW) standard [19], [20] of the European Space Agency
(ESA) in the automotive field. This protocol provides a high
level of fault-tolerance at data rates up to 200 Mb/s. SpW
has already demonstrated to be an effective solution in avionic
and aerospace systems for cruise control, aerial surveillance,
and scientific missions that use high-bandwidth instruments
(cameras, radars, and X-ray detectors) requiring reliable high-
speed networks. Several space missions in Europe, U.S., and
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