ST STM32L4 Series, User Manual

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SM CODE HASH_SM_1
Detailed implementation
Message digest computation performed by HASH module is composed by several data
manipulations and checks. A major part of the hardware random failures affecting HASH
module leads to algorithm violations/errors, and so to decoding errors on the receiver side.
Error reporting Several error condition can happens, check functional documentation.
Fault detection time Depends on implementation
Addressed fault model Permanent/transient
Dependency on Device configuration HASH module available only on specific part numbers
Initialization Depends on implementation
Periodicity Continuous
Test for the diagnostic
Direct test procedure for HASH efficiency is not available. HASH run-time hardware
failures leading to disabling related collateral protection fall into multiple-fault scenario, from
IEC61508 perspective. Related failures are adequately mitigated by the combination of safety
mechanisms reported in this table, field Multiple-fault protection.
Multiple-fault protection
HASH_SM_0: Periodic read-back of HASH configuration registersCPU_SM_0: Periodic core
self-test software
Recommendations and known limitations
This detection capability can be used to implement software-based tests (by processing
a predefined message and further checking the expected results) which can be executed
periodically to early detect HASH failures before its use by application software.
Note: Hardware random failures consequences on potential security features violations are not analyzed in this
manual.
3.6.29 True random number generator (RNG)
Table 102. RNG_SM_0
SM CODE RNG_SM_0
Description Periodic read-back of RNG configuration register
Ownership End user
Detailed implementation
This method must be applied to RNG configuration register RNG_CR.
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 RNG module available only on specific part numbers
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
Table 103. RNG_SM_1
SM CODE RNG_SM_1
Description RNG module entropy on-line tests
Ownership ST and End user
UM2305
Hardware and software diagnostics
UM2305 - Rev 10
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