SM CODE
ADC_SM_2
Addressed fault model
Depends on implementation
Dependency on
Device
configuration
None
Initialization
Depends on implementation
Periodicity
Continuous
Test for the diagnostic
Not applicable
Multiple-fault protection
CPU_SM_0: Periodic core self-test software
Recommendations and known limitations
The implementation and the related diagnostic efficiency of this safety mechanism are strongly
application-dependent.
Table 75.
ADC_SM_3
SM CODE
ADC_SM_3
Description
Periodic software test for ADC
Ownership
End user
Detailed implementation
The method is implemented acquiring multiple signals and comparing the read value with
the expected one, supposed to be know. Method can be implemented with different level of
complexity:
•
Basic complexity: acquisition and check of upper or lower rails (VDD or VSS) and
internal reference voltage
•
High complexity: in addition to basic complexity tests, acquisition of a DAC output
connected to ADC input and checking all voltage excursion and linearity
Error reporting
Depends on implementation
Fault detection time
Depends on implementation
Addressed fault model
Permanent
Dependency on
Device
configuration
None
Initialization
Depends on implementation
Periodicity
Periodic
Test for the diagnostic
Not applicable
Multiple-fault protection
CPU_SM_0: Periodic core self-test software
Recommendations and known limitations
Combination of two methods with different complexity can be used to better optimize test
frequency in high-demand safety functions.
Table 76.
ADC_SM_4
SM CODE
ADC_SM_4
Description
1oo2 scheme for ADC inputs
Ownership
End user
Detailed implementation
This safety mechanism is implemented using two different SAR ADC channels belonging to
separate ADC modules to acquire the same input signal.
Application software
checks the
coherence between the two readings.
Error reporting
Depends on implementation
Fault detection time
Depends on implementation
Addressed fault model
Permanent/transient
Dependency on
Device
configuration
None
Initialization
Depends on implementation
Periodicity
On demand
UM2305
Hardware and software diagnostics
UM2305
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Rev 10
page 47/110