Task: Specify HWFunction Details
This task decomposes the functionality of a hardware element, such as sensor or actuator, and specifies it in more detail.
Hardware elements connect the software to the plant and provide a logical path. This task defines the logical path, or transfer function, of a certain hardware element.
Purpose
The purpose of this task is to decompose and define the functionality of a hardware element, such as sensor or actuator.
Relationships
Main Description
This task specifies and details a certain HW function representing the ”behavior” of a hardware element such as sensor, programmable logic or amplifier, i.e. those that do not execute software.
A hardware function is decomposed into subfunctions and its internal behaviour is detailed or even formalized. The detailing and formalization of the internal behaviour can for instance be done by providing an executable model of the function, for instance by state machines and Simulink models.
During the decomposition and detailing of the hardware function, new information may emerge that calls for a change in the interfaces of the hardware function. For that reason, it is allowed to modify also the interfaces of the function, although it is not of primary concern for this task. This requires, however, close collaboration with the FDA architect.
In the decomposition and modeling process, certain assumptions and constraints on the environment and on the hardware platform may be derived. This is also to be documented in a separate work product.
Steps
Specify hardware function
This step decomposes the hardware function into subfunctions. The specification involves structuring and decomposition of functions to meet needs on allocation, sourcing, re-use, criticality, performance, etc.
Modify interfaces if necessary
This step may modify the interfaces specified by the top-level design, if new needs or findings are discovered during the detailed design of the function. However, this requires close cooperation with the FDA architect.
Identify design constraints
Assumptions and constraints that have been derived during the detailing process are identified and documented in a separate work product.
Properties
Multiple Occurrences
Event Driven
Ongoing
Optional
Planned
Repeatable