ST STM32L4 Series, Руководство пользователя

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Information provided for a function or peripheral applies to all instances of such function or peripheral on Device .
Refer to its reference manual or/and datasheet for related information.
The implementation guidelines reported in the following section are for reference only. The safety verification
executed by ST during the
Device safety analysis and related diagnostic coverage figures reported in this manual
(or related documents) are based on such guidelines. For clarity, safety mechanisms are grouped by Device
function.
Information is organized in form of tables, one per safety mechanism, with the following fields:
SM CODE Unique safety mechanism code/identifier used also in FMEA document. Identifiers use the scheme
mmm_SM_x where mmm is a 3- or 4-letter module (function, peripheral) short name, and x is a
number. It is possible that the numbering is not sequential (although usually incremental) and/or that
the module short name is different from that used in other documents.
Description Short mnemonic description
Ownership ST: method is available on silicon.
End user : method must be implemented by End user through Application software modification,
hardware solutions, or both.
Detailed
implementation Detailed implementation sometimes including notes about the safety concept behind the introduction
of the safety mechanism.
Error reporting Describes how the fault detection is reported to Application software .
Fault detection time Time that the safety mechanism needs to detect the hardware failure.
Addressed fault
model Reports fault model(s) addressed by the diagnostic (permanent, transient, or both), and other
information:
•
If ranked for Fault avoidance : method contributes to lower the probability of occurrence of a
failure
• If ranked for Systematic : method is conceived to mitigate systematic errors (bugs) in
Application software design
Dependency on
Device configuration Reports if safety mechanism implementation or characteristics change among different Device part
numbers.
Initialization Specific operation to be executed to activate the contribution of the safety mechanism
Periodicity Continuous : safety mechanism is active in continuous mode.
Periodic: safety mechanism is executed periodically
(1)
.
On-demand: safety mechanism is activated in correspondence to a specified event (for instance,
reception of a data message).
Startup: safety mechanism is supposed to be executed only at power-up or during off-line
maintenance periods.
Test for the
diagnostic Reports specific procedure (if any and recommended) to allow on-line tests of safety mechanism
efficiency. If no specific procedure applies (as for the majority of safety mechanisms), the field
indicates
Not applicable .
Multiple-fault
protection Reports the safety mechanism(s) associated in order to correctly manage a multiple-fault scenario
(refer to
Section 4.1.3 Notes on multiple-fault scenario ).
Recommendations
and known limitations Additional recommendations or limitations (if any) not reported in other fields.
1. In CM systems, safety mechanism can be accounted for diagnostic coverage contribution only if it is executed at least once
per PST. For LD and HD systems, constraints from IEC61508-2, 7.4.5.3 must be applied.
3.6.1
Arm
®
Cortex
®
-M4 CPU
Table 3. CPU_SM_0
SM CODE CPU_SM_0
Description
Periodic core self-test software for Arm
®
Cortex
®
-M4 CPU .
UM2305
Hardware and software diagnostics
UM2305 - Rev 10
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