NASA Office of Logic Design

A scientific study of the problems of digital engineering for space flight systems,
with a view to their practical solution.

Spaceborne Processors and Avionics

Commercial_Processors

History of the Microprocessor^XL

Processor Papers

AGC_History   Along with information on the Apollo Guidance Computer, a lot of papers, reports, and books about "older" processors.

Commercial Processor Papers

Verification of Processors

1802	Space Shuttle	80x86, Pentium, and Peripherals
8051	87C51	69R000
Alpha	ARM Processors	SPARC (including LEON)
MIL-STD-1750A	29CPL154	Mongoose
RH32	RHDSP24	8085
21020	PowerPC	Laptops In Space
X2000	68xxx	RTX2010 and Other Forth Processors
NSSC-1	ISS	AP-101
Apollo Computers	X-33 Avionics	SHARC

 

General Spaceflight Computers

Commercial Processors

IA-64 Processor

Drive-by-Wire

notes

Verification of Processors

SAFETY-SPECIFIC ANALYSIS AS ADDITIONAL DESIGN ASSURANCE FOR MICROPROCESSORS Håkan Forsberg, Saab Avitronics, Jönköping, Sweden 27th Digital Avionics Systems Conference October 26-30, 2008	Abstract    In this paper we discuss the use of safety-specific analysis (SSA) as additional design assurance of modern microprocessors. SSA is a method to derive and validate safety-specific requirements about internal operations of a component.    We suggest and discuss a mixed component assurance approach based on on-chip service history, on-chip architectural mitigation techniques (including turning off some parts) and safety-specific analysis on different parts of the microprocessor. With this approach we believe that it might be possible to gain certification credit for the complete microprocessor even if some on-chip parts are partially or even completely new.    We also show why it will be very hard to perform safety-specific analysis on a complete modern microprocessor. A modern microprocessor is simply too complex and manipulates data in a too complex manner to be able to analyze for safety-specific aspects.
Microprocessor Evaluations for Safety-Critical, Real-Time Applications: Authority for Expenditure No. 43 Phase 1 Report DOT/FAA/AR-06/34 Office of Aviation Research and Development December, 2006	Abstract    The intent of this report is to provide findings about safety issues in using today’s microprocessors on aircraft. It considers the applicability of RTCA/DO-254 to microprocessors, documents potential safety concerns when using modern microprocessors on aircraft, and proposes potential approaches for addressing these safety concerns.    The project is being performed in two phases with participation from avionic system developers (BAE Systems, The Boeing Company, and Smiths Aerospace) and Federal Aviation Administration organizations responsible for aircraft safety research and development. Phase 1 established the project scope and identified the research parameters as documented in this report.    This report presents an assessment of existing certification guidelines towards certification of microprocessors. It indicates that new validation processes are required in addition to the existing ones. The report identifies that microprocessor obsolescence management may become a significant problem in the future due to rapidly changing designs. This report also addresses unpredictable issues in computational components of the microprocessors that may lead to safety concerns in avionics applications. The microprocessor testing and evaluation trends are presented, and several safety concerns are identified related to the testing and validation.    In the next phase, studies will be made to incorporate a set of recommended guidelines towards selection and qualification of microprocessors in the certification process.
Microprocessor Evaluations for Safety-Critical, Real-Time Applications: Authority for Expenditure No. 43 Phase 2 Report DOT/FAA/AR-08/14 Air Traffic Organization Operations Planning Office of Aviation Research and Development June, 2008	Abstract    The intent of this report was to provide findings about safety issues in using today’s microprocessors on aircraft. The research effort considered the applicability of RTCA/DO-254 to microprocessors, documented potential safety concerns when using modern microprocessors on aircraft, and proposed potential approaches for addressing these safety concerns.    The project was performed in multiple phases with participation from avionic system developers (BAE Systems, The Boeing Company, Lockheed Martin, and Smiths Aerospace) and Federal Aviation Administration organizations responsible for aircraft safety research and development. Phase 1 established the project scope and identified the research parameters. Phase 1 reviewed the available literature and surveyed microprocessor users to identify the issues and potential solutions associated with the use of microprocessors in regulated safety-critical applications. Phase 2, documented in this report, developed the project objectives and found an approach to work toward the solution of these issues and the achievement of these objectives. Phase 3 is intended to validate this approach and continue the development of processes, services, and prototype tool development. These results will be documented in a Microprocessor Selection and Evaluation Handbook to facilitate application to real-world, safety-critical applications.    Current trends toward using commercial off-the-shelf (COTS) microprocessors present safety challenges, especially with growing design complexity, the vast array of supported features, and limited design documentation. A formal framework for the approval of COTS microprocessors in aerospace systems is essential. This report proposes a Microprocessor Approval Framework that is applicable to COTS microprocessors.
Microprocessor Evaluations for Safety-Critical, Real-Time Applications: Authority for Expenditure No. 43 Phase 3 Report DOT/FAA/AR-08/55 Air Traffic Organization Operations Planning Office of Aviation Research and Development February, 2009	Abstract    This report discusses the findings concerning safety issues in using today’s commercial off-the-shelf (COTS) microprocessors on aircraft. The report addresses the applicability of RTCA/DO-254 to microprocessors, documents potential safety concerns when using modern COTS microprocessors on aircraft, and proposes potential approaches for addressing these safety concerns.    The research was performed in multiple phases with participation from avionic system developers (BAE Systems, The Boeing Company, Lockheed Martin, and Smiths Aerospace) and Federal Aviation Administration organizations responsible for aircraft safety research and development. Phase 1 established the project scope and identified the research parameters, as well as reviewed the available literature and surveyed microprocessor users to identify the issues and potential solutions associated with the use of COTS microprocessors in regulated, safety-critical applications. Phase 2 developed the project objectives and found an approach to work toward the solution of these issues and the achievement of these objectives. Phase 3, documented in this report, evaluated the proposed approach and continued the development of processes, services, and prototype tool development. Phase 4, depending heavily on industry experience, will attempt to determine if new approaches can be developed to ensure system safety and provide more effective methods to accumulate safety evidence for certification while reducing the time and cost to develop and certify complex systems. These results will be documented in a Microprocessor Selection and Evaluation Handbook to facilitate application to real-time, safety-critical applications.
Microprocessor Evaluations for Safety-Critical, Real-Time Applications: Authority for Expenditure No. 43 Phase 4 Report *** GET THIS REPORT WHEN IT COMES OUT ***

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