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Forum: Reliability & Maintainability Questions and Answers

Topic: Reliability & Maintainability Questions and Answers

Topic Posted by: Reliability & Maintainability Forum ( )
Organization: System Reliability Center
Date Posted: Mon Aug 31 12:47:36 US/Eastern 1998

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Original Message:

Posted by: Erica
Date posted: Mon Mar 5 16:13:47 US/Eastern 2007
Subject: SEU/MBU Probability Evaluation
We need to evaluate the probability of occurrence of SEU/MBU effects in the our chip (memories, registers, state machines)on aircraft environment. In particular we know if there is a formula that allows to calculate this probability and what type of parameters we need to know. Is there a connection between a SEU and MBU occurrence probability (in upset/bit/hour) and the Average Atmospheric Flux that the aircraft is exposed? What type of relation? Thank you in advance.


Subject: Upset Events
Reply Posted by: B. W. Dudley
Organization: System Reliability Center
Date Posted: Fri Mar 9 13:23:08 US/Eastern 2007
The analysis of single event upsets and multiple bit upsets is a difficult analysis as one needs to determine the LET(linear energy transfer)and the cross section of the bit. The multiplication of the device LET function and the cross section will produce the upsets per bit per day. I would suggest that you read a paper from the 1995 Proceedings of the Annual Reliability and Maintainability Symposium page 447-449 for a description of the technique. The Aerospace Corporation has report on this condition which can be seen at: //

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