Standardized System Software for Automotive Applications - Networked Embedded Systems - page 437

Function inhibition manager ( Fim ): The Function Inhibition Manager is a submodule of the
AUTOSAR diagnostic module. he Fim is responsible for providing an “execution control mecha-
nism for the runnables” of application software components and system software modules. By means
of the Fim , these runnables can be inhibited (i.e., deactivated) according to the Fim 's static con-
figuration. The functionalities of the runnables are assigned to a unique function identifier (FID)
along with an inhibit conditions for that particular FID. he functionalities poll for the permission
state of their respective FIDs before execution. If an inhibit condition is true for a particular FID, the
corresponding functionality is not executed anymore.
he Fim is closely related to the Dem as diagnostic events and their status information can serve
as possible inhibit conditions. Hence, functionality which needs to be stopped in case of a failure can
be represented by a particular FID. If the failure is detected and the event is reported to the Dem ,the
Fim then inhibits the FID and therefore the corresponding functionality.
Diagnostic event manager ( Dem ): Like the Dcm module and the Fim module, the Diagnostic Event
Manager module is a submodule of the diagnostic module within AUTOSAR. he Dem is responsi-
ble for “processing and persistently storing diagnostic events/errors” ∗ and associated data (so-called
freeze frame data). To facilitate the persistent storage of these diagnostic trouble codes (DTCs), the
Dem makes use of the services provided by the NvM . Application software components as well as
other system software modules can raise diagnostic event by means of Dem API calls.
The diagnostic events registered by the Dem serve as triggers for state updates of the Fim and thus
might lead to the inhibition of certain runnables. Upon request of the Dcm ,the Dem provides an up-
to-date list of the currently stored DTCs, which are then sent to a tester client by means of the Dcm
services.
Watchdog driver ( Wdg ): This module provides services for initialization, changing of the operation
mode ( Fast , Slow , Off ) and “triggering the ECU's watchdog device.” In case an ECU provides
multiple different watchdog devices (e.g., internal and external devices), a dedicated Wdg module
hastobepresentforeachofthedevices.
Watchdog interface ( WdgIf ): In case of more than one watchdog device and corresponding Watch-
dog Driver (e.g., both an internal software watchdog and an external hardware watchdog) is being
used on an ECU, the Watchdog Interface module allows the Watchdog Manager module (see below)
to select the correct Watchdog Driver—and thus the watchdog device—via a device index, while
retaining the API and functionality of the underlying driver. Thus, the WdgIf module provides
“uniform access to services of the underlying Watchdog Drivers” like mode switching and triggering.
Watchdog manager ( WdgM ): he Watchdog Manager module is intended to “supervise the (periodic)
execution” of application software components or other system software modules. Via the services
provided by the WdgIf ,the WdgM abstracts from the triggering of hardware watchdog entities and
itself provides supervision capabilities to an (theoretically) infinite number of clients. he WdgM pro-
vides an individual port for each supervised client, where the clients have to indicate their proof of
aliveness by updating an alive-counter. Within a cyclic scheduled main processing function of the
WdgM , the alive-counters of all supervised clients are checked against their own independent timing
constraints and a “global supervision status” is derived. Based on this global supervision status, the
WdgM decides whether or not to trigger the hardware watchdog via the WdgIf 's API. Hereby, the set
of supervised clients and their individual timing constraints is defined by configurable parameters of
the WdgM .
Development error tracer ( Det ): he Development Error Tracer module is the central instance where
all other system software modules “report detected development errors” to. The API parameters

∗

UDSandKWPusethetermDTCfortheseevents.