SM CODE
VSUP_SM_2
Error reporting
Reset signal generation
Fault detection time
Depends on implementation (watchdog timeout interval)
Addressed fault model
Permanent
Dependency on
Device
configuration
None
Initialization
IWDG activation. It is recommended to use
Hardware watchdog
in Option byte settings (IWDG
is automatically enabled after reset).
Periodicity
Continuous
Test for the diagnostic
Refer to CPU_SM_6.
Multiple-fault protection
CPU_SM_1: Control flow monitoring in
Application software
Recommendations and known limitations
In specific part numbers, IWDG can be fed by a power supply independent from the one used
for CPU core and main peripherals. Such diversity helps to increase the protection guaranteed
by IWDG from main power supply anomalies.
The adoption of an external watchdog (refer to CPU_SM_5) adds further diversity.
Table 37.
VSUP_SM_3
SM CODE
VSUP_SM_3
Description
Internal temperature sensor check
Ownership
End user
Detailed implementation
The internal temperature sensor must be periodically tested in order to detect abnormal
increase of the die temperature – hardware faults in supply voltage system may cause
excessive power consumption and consequent temperature rise.
Error reporting
Depends on implementation
Fault detection time
Depends on implementation
Addressed fault model
Permanent
Dependency on
Device
configuration
None
Initialization
None
Periodicity
Periodic
Test for the diagnostic
Not applicable
Multiple-fault protection
CPU_SM_0: Periodic core self-test software
Recommendations and known limitations
This method also mitigates the probability of common-cause failure due to excessive
temperature, affecting
Device
.
Refer to the
Device
datasheet to set the threshold temperature.
Table 38.
VSUP_SM_4
SM CODE
VSUP_SM_4
Description
Peripheral voltage monitoring (PVM)
Ownership
ST
Detailed implementation
The device features an embedded programmable voltage detector (PVM) that monitors and
compares the three independent power supplies to thresholds. An interrupt can be generated
when an independent power supply drops below the threshold or when it is higher than the
threshold.
Error reporting
Interrupt generation on specific EXTI lines
Fault detection time
Depends on threshold programming. Refer to functional documentation.
Addressed fault model
Permanent/transient
UM2305
Hardware and software diagnostics
UM2305
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Rev 10
page 28/110