SM CODE
ATIM_SM_3
Recommendations and known limitations
Efficiency versus transient failures is linked to final application characteristics. We define as
Tm the minimum duration of PWM wrong signal permanence (wrong frequency, wrong duty, or
both) required to violate the related safety function(s). Efficiency is maximized when execution
test frequency is higher than 1/Tm.
Table 111.
ATIM_SM_4
SM CODE
ATIM_SM_4
Description
Lock bit protection for timers
Ownership
ST
Detailed implementation
This safety mechanism allows
End user
to lock down specified configuration options, thus
avoiding unintended modifications by
Application software
. Therefore, it addresses software
development systematic faults.
Error reporting
Not applicable
Fault detection time
Not applicable
Addressed fault model
None (Fault avoidance)
Dependency on
Device
configuration
None
Initialization
Lock protection must be enabled using LOCK bits in the TIMx_BDTR register.
Periodicity
Continuous
Test for the diagnostic
Not applicable
Multiple-fault protection
Not applicable
Recommendations and known limitations
This method does not address timer configuration changes due to soft errors.
Note:
IRTIM is not individually mentioned here as its implementation is mostly based on general-purpose timer
functions. Refer to related prescriptions.
3.6.32
Basic timers (TIM6/7)
Table 112.
GTIM_SM_0
SM CODE
GTIM_SM_0
Description
Periodic read-back of configuration registers
Ownership
End user
Detailed implementation
This method must be applied to basic timer 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
Refer to NVIC_SM_0
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 64/110
