AN3077 datasheet(23/82 Pages) STMICROELECTRONICS

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AN3077

Functional safety requirements for application software

inputs which have edge detection interrupts (See Figure 3 for details).

Mandatory: One channel must be addressed by eTimer_0, and the other by eTimer_1.

Note:

Rationale: Two different eTimers must be used to avoid CCF (eTimer_0 and eTimer_1

belonging to different lakes).

For each signal, the SIUL can provide additional channels to support interrupt-based

reading.

Mandatory: In this configuration, the SIUL must be correctly configured to forward one or

two interrupt-based event readings.

Note:

Rationale: To configure pads used by this safety function

Mandatory: The input pads must not be physically adjacent (see Section 7, I/O pin/ball

configuration for details).

Note:

Rationale: To minimize CCF

3.13.3.1.2

Safety Integrity Functions

The safety integrity is achieved by duplicate reads and software comparison by the

processing function (See Figure 3).

Mandatory: The application software must implement the following tests:

●

ETIMER0_SWTEST_REGCRC

●

ETIMER1_SWTEST_REGCRC

●

SIUL_SWTEST_REGCRC

Note:

Rationale: To verify that the configuration of the modules used by this safety function

compare with what is expected

Rationale: To avoid CCF caused by improper configuration of the pads

Mandatory: The application software must implement the test ENCI_SWTEST_CMP, which

compares signals acquired from each channel.

Note:

Rationale: To verify that the two sets of data compare

AN3077 Datasheet(PDF) 23 Page - STMicroelectronics