SPRUI78D March 2019 – January 2022 TMS320F28075 , TMS320F28075-Q1 , TMS320F28076 , TMS320F28374D , TMS320F28374S , TMS320F28375D , TMS320F28375S , TMS320F28375S-Q1 , TMS320F28376D , TMS320F28376S , TMS320F28377D , TMS320F28377D-Q1 , TMS320F28377S , TMS320F28377S-Q1 , TMS320F28378D , TMS320F28378S , TMS320F28379D , TMS320F28379D-Q1 , TMS320F28379S

8 Terms and Definitions

IEC 60730: The IEC 60730 standard covers mechanical, electrical, electronic, EMC, and abnormal operation of ac appliances. It is used in the design of design of white goods and other appliances to improve customer safety using software test libraries developed in accordance with this standard.
IEC 61508: Functional safety standard for E/E/PE safety-related systems. This is intended to be a basic functional safety standard applicable to all kinds of industry. It defines functional safety as: “part of the overall safety relating to the EUC (Equipment Under Control) and the EUC control system which depends on the correct functioning of the E/E/PE safety-related systems, other technology safety-related systems and external risk reduction facilities” [4].
ISO 13849: provides safety requirements and guidance for the design and integration of safety-related parts of control systems (SRP/CS), including software design.
M out of N (MooN) architecture: A safety instrumented system where ‘M’ channels out of ‘N’ channels are required for functionally safe operation. (for example, 2oo3, 2 out of 3 architecture, where majority voting is used to implement a safety function).
Figure 8-1 ISO 26262 Illustration of Item, System, Component, Hardware Part and Software Unit
M out of N Channel Architecture with diagnostics (MooND).
Functional Safety: Part of the overall safety relating to the EUC and the EUC control system that depends on the correct functioning of the E/E/PE safety-related systems and other risk reduction measures
Item: system or array of systems to implement a function at the vehicle level, to which ISO 26262 is applied (for example, power steering of a car).
Element: System or part of a system including components, hardware, software, hardware parts, and software units.
System: set of elements that relates at least a sensor, a controller and an actuator with one another
Component: Non-system level element that is logically and technically separable and is comprised of hardware parts and software units.
Hardware part: Hardware that cannot be subdivided (for example, CPU).
Software unit: Atomic level software component of the software architecture that can be subjected to stand-alone testing (for example, SRAM test module).
Failure: termination of the ability of an element, to perform a function as required.
Failure mode: manner in which an element or an item fails.
Single Point Fault: Fault in an element that is not covered by a safety mechanism and that leads directly to the violation of a safety goal.
Single-point failure: Failure that results from a single-point fault and that leads directly to the violation of a safety goal.
Multiple-point fault: Individual fault that, in combination with other independent faults, leads to a multiple-point failure.
Multiple-point failure: Failure resulting from the combination of several independent faults, which leads directly to the violation of a safety goal. For a multiple-point failure to directly violate a safety goal, presence of all independent faults is necessary.
Multiple-point fault detection interval: time span to detect multiple-point fault before it can contribute to a multiple-point failure.
Latent fault: multiple-point fault whose presence is not detected by a safety mechanism nor perceived by the driver within the multiple-point fault detection interval.
Functional Safety Assessment: Investigation, based on evidence, to judge the functional safety achieved by one or more E/E/PE safety-related systems and/or other risk reduction measures.
Functional Safety Audit: Systematic and independent examination to determine whether the procedures specific to the functional safety requirements to comply with the planned arrangements are implemented effectively and are suitable to achieve the specified objectives.
Hazard and Risk Analysis (IEC 61508)/Hazard Analysis and Risk Assessment (ISO 26262): An end equipment level functional safety analysis that is used to identify safety functions and/or functional safety goals. This process also establishes the SIL (IEC 61508) or ASIL (ISO 26262), which defines the level of risk reduction necessary per safety function and/or functional safety goal.
Process Tailoring: The act of changing a development process or functional safety lifecycle to match needs of a business engagement. Requirements can be moved from phase to phase or performed by other developers, but removal of process requirements is not allowed.
Quality Managed: Describes a design element which is developed compliant to applicable quality standards but is not developed compliant to applicable functional safety standards. It may be possible to use a quality managed design element in a specific functional safety design contingent upon results of a functional safety qualification.
Safety Requirement Decomposition: Safety requirements decomposition is the process in which safety requirements are split into a series of redundant safety requirements at a lower level of abstraction in order to support tailoring of the SIL (ISO 61508)/ASIL (ISO 26262) compliance requirements of design elements at the lower level of abstraction. For example, a requirement for a peripheral function with high safety integrity might be addressed by redundant instances of a peripheral with lower safety integrity.
For the full list of applicable terms and their definitions for ISO 26262, see the ISO 26262-1:2018, Road vehicles — Functional safety — Part 1: Vocabulary.
For the full list of applicable terms and their definitions for IEC 61508, see the IEC 61508, Functional safety of electrical/electronic/programmable electronic safety-related systems – Part 4: Definitions and abbreviations.