Image Processing Reference
In-Depth Information
Actuator
Sensor
Sensor
Environmental
interface
MCU
Network
interface
CC
CC
FIGURE .
Hardware architecture—ECU level.
topology used for the interconnection is basically arbitrary; however, bus, star, and ring topologies
are the most common topologies in today's cars. his “network level” represents the medium level of
abstraction.
On the lowest level of abstraction, the “ECU level” (Figure .), the major parts of an ECU are
of interest. An ECU comprises one or more microcontroller units (MCUs) as well as one or more
communication controllers (CCs). In most cases, exactly one MCU and one CC are used to build up
an ECU. To be able to control physical processes in the car (e.g., control the injection pump of an
engine), the ECU's MCU is connected to actuators via the analog or digital output ports of the MCU.
To provide means to obtain environmental information, sensors are connected to the MCUs analog
or digital input ports. We call this interface the ECU's environmental interface. he CC(s) facilitate(s)
the physical connectivity of the ECU to the respective network(s). We call this interface of an ECU
the ECU's network interface.
18.3 OSEK/VDX
he OSEK/VDX standard was the result of the endeavors of major car manufacturers and their sup-
pliers to create a standardized software infrastructure for automotive electronics. his standard was
initially designed for applications in the area of automotive body electronics or for the power train
where autonomous control units build up a loosely coupled network. It comprises the following
standardized components:
OSEK OS
: The OSEK OS is an event-driven-operating system intended for hard real-time applica-
tions. OSEK provides services for task management, intertask communication by means of messages,
events, resources, alarms, and interrupt handling.
OSEK NM
: OSEK NM provides network management (NM) facilities, which take care of a controlled
coordinated start-up and shutdown of the communication of multiple ECUs within a network.
OSEK COM
: OSEK COM offers services to transfer data between different tasks and/or interrupt
service routines (ISRs) residing on the same ECU (internal communication) or possibly being
distributed over several ECUs (external communication).
OSEKtime OS
: OSEKtime OS is a time-driven-operating system designed for minimal-operating
system footprint and deployment in safety-related applications.
