Υπολογισμός AVF για επεξεργαστή MIPS

Εμμανουήλ, Ευάγγελος Ι.

Master Thesis

Author

Εμμανουήλ, Ευάγγελος Ι.

Date

2012-06-08

Abstract

As IC and microprocessor manufacturing technologies improve, the more vulnerable these devices become to alpha particles and neutron strikes. The cost of protecting the internal structures of a CPU from such events is significant. AVF is the fraction of such faults resulting in user-visible errors. Thus, AVF can be used as a design tool enabling informed decisions to be made regarding which structures should be protected and in what way in order to minimize radiation hardening costs. This dissertation shows the development of a simulator and a model of a core MIPS32 architecture based microprocessor with the goal of computing it’s AVF. Various experiments where executed which gave AVF values ranging from 33.38% to 36.45%. These results suggest that it is indeed not necessary to protect every single bit inside a microprocessor. Significant variations where observed among the AVF values of individual hardware structures. Specifically, the IF/ID register had AVF values from 47.64% to 57.80%, ID/EX AVF ranged from 38.99% to 45.33%, EX/MEM was from 16.36% to 26.95% and MEM/WB had AVF values from 22.07% to 31.07%. Another example to this are the opcode bits of the PC register with an AVF of 100% since any error in those bits will lead to the execution of an incorrect operation.