Table 26. Flash_Sm_3; Table 27. Flash_Sm_4; Table 28. Flash_Sm_5 - ST STM32L4 Series User Manual

SM CODE
Description
Ownership
Detailed implementation
Error reporting
Fault detection time
Addressed fault model
Dependency on Device configuration
Initialization
Periodicity
Test for the diagnostic
Multiple-fault protection
Recommendations and known limitations
SM CODE
Description
Ownership
Detailed implementation
Error reporting
Fault detection time
Addressed fault model
Dependency on Device configuration
Initialization
Periodicity
Test for the diagnostic
Multiple-fault protection
Recommendations and known limitations
SM CODE
Description
Ownership
Detailed implementation
Error reporting
UM2305 - Rev 10
Table 26. FLASH_SM_3
Option byte write protection
ST
This safety mechanism prevents unintended writes on the option byte. The use of this method
is encouraged to enhance end application robustness for systematic faults.
Write protection exception
Not applicable
None (systematic only)
None
None (always enabled)
Continuous
Not applicable
CPU_SM_0: Periodic core self-test software
This method addresses systematic faults in software application and it have zero efficiency in
addressing hardware random faults affecting the option byte value during running time. No DC
value is therefore associated.
Table 27. FLASH_SM_4
Static data encapsulation
End user
If static data are stored in Flash memory, encapsulation by a checksum field with encoding
capability (such as CRC) must be implemented.
Checksum validity is checked by Application software before static data consuming.
Depends on implementation
Depends on implementation
Permanent/transient
None
Depends on implementation
On demand
Not applicable
CPU_SM_0: Periodic core self-test software
None
Table 28. FLASH_SM_5
Option byte redundancy with load verification
ST
During option byte loading after each power-on reset, the bit-wise complementarity of the
option byte and its corresponding complemented option byte is verified. Mismatches are
reported as an error.
Option byte error (OPTVERR) generation
Hardware and software diagnostics
FLASH_SM_3
FLASH_SM_4
FLASH_SM_5
UM2305
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