Appendix 2.8 to ETSO-C153a – Integrated Modular Avionics (IMA) Platform and Module Minimum Performance Standard (MPS)

CLASS DH: Display Head

1. Purpose and scope

1.1. Introduction

This Appendix contains the Minimum Performance Standards (MPS) for the CLASS DH Intended Function: Display Head.

These standards specify characteristics that should be useful to designers, manufacturers, installers and users of the module.

1.2. Definitions

For ETSO-C153a CLASS DH, the IMA module provides shared resources in terms of a display area between hosted applications, components and/or modules.

The following definitions are used:

— Display Unit: a set of physical components (hardware and/or software) in charge of managing a display area (or a part thereof).

— Display Area: a surface where some visual information can be depicted by one or several Display Unit(s) based on received Graphical Threads.

— Graphical Thread: a set of graphical information received as input by the Display Head from one or more IMA application(s), component(s) and/or module(s).

— Display Thread: a set of depiction information for which a level of isolation on the Display Area is guaranteed by the Display Head.

In the context of DH class, the ‘concurrent item’ defined in Appendix 2.1, paragraph 1 means ‘Display Thread’.

1.3. Intended Function

For ETSO-C153a CLASS DH, the intended function is to provide the capability to share one display area supplied by one or several display unit(s).

The intended function of such an IMA module is to offer the capability to depict graphical information received from (an) IMA application(s), component(s) and/or module(s) on one Display Area.

The following figure provides an overview of the above-mentioned intended function and the associated interfaces:

Figure 24: IMA module overview of ETSO-C153a CLASS DH

2. Requirements

2.1. Functional requirements for ETSO-C153a CLASS DH

DH.a) The IMA module shall provide to hosted applications, modules and/or components, a Display Area Resource which has the capability to render visual graphical information.

DH.b) The IMA module shall be fully or partially compliant with the MPS as from the applicable release of ETSO-C113.

Note 1: these performance requirements are additional to those applicable in Appendix 2.1 — COMMON.

Note 2: for Display Head modules without a Graphics generation function, compliance demonstration to some ETSO-C113 requirements might not be possible. In such cases, the applicant shall submit in the compliance data package the list of requirements that need further demonstration with regard to the C113 requirements providing a relevant justification.

DH.c) The IMA module shall provide to hosted applications, modules and/or components the capability to share a Display Area resource managed through a logical or physical interface.

Figure 25: The relationship between CLASS DH Display Head elements

2.2. Characterisation requirements for ETSO-C153a CLASS DH

DH.d) In addition to the Common Requirement 0, the characterisation shall address the safety aspects of delay and/or frozen information.

DH.e) In addition to Common Requirement 0, the characterisation shall include any data needed to evaluate the Worst-Case Display Elaboration Time of managed threads, and the characteristics required by the applicable release of SAE AS8034 (as per the applicable revision of ETSO-C113).

DH.f) The additional activities to be performed by the user related to the applicable release of ETSO-C113 for complete compliance demonstration shall be included in the characterisation for gap identification.

3. Verification procedures

The following table gives a verification method for each MPS; nevertheless, an alternative method may be proposed to the certification authority:

Requirement identifier	Verification method	Test under normal conditions	Test under environmental conditions	Comment
DH.a)	T	Y	Y
DH.b)	(2)	(2)	(2)
DH.c)	T	Y	Y
DH.d)	T/A*	Y
DH.e)	A
DH.f)	A

Table 8: Verification Acceptance Criteria

(A*) means that verification by the Analysis method is possible for the item that cannot be tested.

Note (1): for the functional subset, see CO.gg.

Note (2): an applicable revision of ETSO-C113 defining the verification requirements of a display function.

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