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SM CODE
CLK_SM_2
Recommendations and known limitations
The adoption of an external watchdog (refer to CPU_SM_5) adds further diversity.
Table 43.
CLK_SM_3
SM CODE
CLK_SM_3
Description
Internal clock cross-measurement
Ownership
End user
Detailed implementation
This method is implemented using TIM15/TIM16/TIM17 capabilities to be fed by the 32 KHz
RTC clock or an external clock source (if available). TIM15/TIM16/TIM17 counter progresses
are compared with another counter (fed by internal clock). Abnormal values of oscillator
frequency can therefore be detected.
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_1: Control flow monitoring in
Application software
CPU_SM_5: External watchdog
Recommendations and known limitations
Efficiency versus transient faults is negligible. It provides only medium efficiency in permanent
clock-related failure mode coverage.
3.6.8
General-purpose input/output (GPIO)
Table 44.
GPIO_SM_0
SM CODE
GPIO_SM_0
Description
Periodic read-back of configuration registers
Ownership
End user
Detailed implementation
This method must be applied to GPIO configuration registers.
Detailed information on the implementation of this method can be found in
Section 3.6.14 Extended interrupt and events controller (EXTI)
.
Error reporting
Refer to NVIC_SM_0
Fault detection time
Refer to NVIC_SM_0
Addressed fault model
Refer to NVIC_SM_0
Dependency on
Device
configuration
GPIO availability can differ according to part number
Initialization
Refer to NVIC_SM_0
Periodicity
Refer to NVIC_SM_0
Test for the diagnostic
Refer to NVIC_SM_0
Multiple-fault protection
Refer to NVIC_SM_0
Recommendations and known limitations
Refer to NVIC_SM_0
UM2305
Hardware and software diagnostics
UM2305
-
Rev 10
page 31/110