The IPT DO-254 Guidance has now been published.
A copy of the report can be downloaded here >>>

Problem:
There is no detailed guidance for the specification and procurement of safe complex electronic hardware, specifically programmable logic devices (PLDs). For the contractor, their development had been specifically addressed by Def Stan 00-54 introduced in 1999. However, the standard has been withdrawn and superseded by the more general Def Stan 00-56 issue 3.

Context:
The functionality of an electronic system built from components on a circuit board can now be provided by the configuration of a single PLD such as an FPGA. Indeed, a processor, memory and an internal bus can be "built up" within an FPGA to provide a "system on a chip". Consequently, PLDs provide an alternative to microprocessor based systems with considerable advantages in terms of size, weight, power and performance.

Challenge:
The specification, design and assurance of programmable logic includes all the issues of software development whereby the safety argument requires assurance from the design process to complement evidence from the conventional testing regime. As well as the "software" design assurance, the development must address the particular hardware issues of PLD design such as signal integrity, clock slew, single event upsets.

Solution: ASSC Guidance based on DO-254
The ASSC has provided a guidance document for IPTs about the acceptance of systems containing programmable logic based on the civil aviation guidelines, DO-254. These are complementary to the DO-178B software guidelines and address the design assurance of airborne electronic hardware, including PLDs.

The guidance is based on a description of the requirements of the DO-254 document and how it could be used to provide the required safety evidence within a Def Stan 00-56 issue 3 framework. The document also collects together basic technical information about PLD technology in Appendices.

	CEH technology - What's available and what are the benefits and issues associated with using the different types
	DO-254 - The use of the guidelines as a means of developing PLDs for safety related and safety critical systems
	Certifications - How does certification differ, if at all, for a system containing CEH

The first of a number of related workshops was undertaken at ERA Leatherhead on the 6th of July 2006 and focused on the first two issues, that is CEH Technology and DO-254. The presentations given are available for download:

	Introduction to Complex Electronic Hardware - Clive Lee [powerpoint] / [pdf]
	Introduction to DO-254 - Clive Lee [powerpoint] / [pdf]
	Practical Experience of Developing an Avionics Application containing CEH to DO-254 - Dr. Duncan Brookes [powerpoint] / [pdf]

Further IPT workshops have been undertaken at RAF Wyton and Abbey Wood in 2007.

For more information please e-mail: era.assc@cobham.com or call: +44 (0) 1372 367141