Reference Safety Architectures - 1Oo2 - ST STM32L4 Series User Manual

3.2.4

Reference safety architectures - 1oo2

1oo2 reference architecture
reference architecture ensuring safety integrity of Compliant item through combining Device internal processes
(implemented safety mechanisms) with external processes WDTe and VMONe. The overall safety integrity is then
ensured by the external voter PEv, which allows claiming
of higher safety integrity levels as per IEC61508-2 Table 3 is therefore possible. Appropriate separation between
the two channels (including power supply separation) should be implemented in order to avoid huge impact of
common-cause failures (refer to
computation is required.
1oo2 reference architecture targets SIL3.
Sensors
UM2305 - Rev 10
(Figure 4) contains two separate channels, either implemented as 1oo1
Section 4.2 Analysis of dependent
Figure 4. 1oo2 reference architecture
VMONe WDTe
PEi PEc
PEd
PEi PEc
PEd
VMONe
hardware fault tolerance (HFT)
failures). However, β and βD parameters
PEo
PEv
PEo
WDTe
UM2305
Compliant item
equal to 1. Achievement
Actuators
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