SFFS222 October 2023 TMS320F2800153-Q1 , TMS320F2800154-Q1 , TMS320F2800155-Q1 , TMS320F2800156-Q1 , TMS320F2800157 , TMS320F2800157-Q1
Information redundancy techniques can be applied via software as an additional runtime diagnostic. There are many techniques that can be applied, such as read back of written values and multiple reads of the same target data with comparison of results.
In order to provide diagnostic coverage for network elements outside the TMS320F280015x MCU (wiring harness, connectors, transceiver), end-to-end safety mechanisms are applied. These mechanisms can also provide diagnostic coverage inside the TMS320F280015x MCU. There are many different schemes applied, such as additional message checksums, redundant transmissions, time diversity in transmissions, and so forth. Most commonly checksums are added to the payload section of a transmission to ensure the correctness of a transmission. These checksums, sequence counter and timeout expectation (or time stamp) are applied in addition to any protocol level parity and checksums. As these are generated and evaluated by the software at either end of the communication, the whole communication path is safed, resulting in end-to-end safing.
Any end-to-end communications diagnostics implemented should consider the failure modes and potential mitigating safety measures described in IEC 61784-3:2016 and summarized in IEC 61784-3:2016, Table 1.