Real-Time Clock Module (Rtc); Table 76. Rtc_Sm_0; Table 77. Rtc_Sm_1 - ST STM32F2 Series User Manual

3.6.17

Real-time clock module (RTC)

SM CODE
Description
Ownership
Detailed implementation
Error reporting
Fault detection time
Addressed fault model
Dependency on MCU configuration
Initialization
Periodicity
Test for the diagnostic
Multiple faults protection
Recommendations and known limitations
SM CODE
Description
Ownership
Detailed implementation
Error reporting
Fault detection time
Addressed fault model
Dependency on MCU
configuration
Initialization
Periodicity
Test for the diagnostic
Multiple faults protection
Recommendations and known
limitations
UM1845 - Rev 4
Table 76.
RTC_SM_0
Periodical read-back of configuration registers
End user
This method must be applied to RTC configuration registers.
Detailed information on the implementation of this method can be found in
Refer to NVIC_SM_0
Refer to NVIC_SM_0
Refer to NVIC_SM_0
Refer to NVIC_SM_0
Refer to NVIC_SM_0
Refer to NVIC_SM_0
Refer to NVIC_SM_0
Refer to NVIC_SM_0
Refer to NVIC_SM_0
Table 77.
RTC_SM_1
Application check of running RTC
End user
The application software implements some plausibility check on RTC calendar or timing data, mainly after a
power-up and further date reading by RTC.
The guidelines for the implementation of the method are the following:
• RTC backup registers are used to store coded information in order to detect the absence of VBAT
during power-off period.
• RTC backup registers are used to periodically store compressed information on current date or time
• The application software executes minimal consistence checks for date reading after power-on
(detecting "past" date or time retrieve).
• Application software periodically checks that RTC is actually running, by reading RTC timestamp
progress and comparing with an elapsed time measurement based on STM32 internal clock or timers
Depends on implementation
Depends on implementation
Permanent and Transient
None
Depends on implementation
Periodical
Not needed
CPU_SM_0: periodical core self-test software
This method provides a limited diagnostic coverage for RTC failure modes. In case of end user application
where RTC timestamps accuracy can affect in severe way the safety function (e.g. medical data storage
devices), it is strongly recommended to adopt more efficient system-level measures
Description of hardware and software diagnostics
RTC_SM_0
RTC_SM_1
UM1845
Section 3.6.5
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