Bit impact factor: Towards making fair vulnerability comparison

Transistors used in microprocessors are shrinking with the advancements in the manufacturing technology. With the help of this scaling on the transistors, operating voltages can be lowered and both computational power and memory capacity can be increased by placing transistors denser. However, smaller transistors lead growth of the soft error vulnerability of the microprocessors. Today, architects generally use Architectural Vulnerability Factor (AVF) as vulnerability metric for their products at the design time. It gives them an idea about how much reliable their system is. AVF considers that the value of a bit is either required for Architecturally Correct Execution (ACE-bit) or not (unACE-bit). Therefore, AVF cannot distinguish the vulnerability impact level of an Architecturally Correct Execution - ACE bit. In this thesis, a new metric is introduced by extending AVF to provide more accurate vulnerability analysis of the bits in the system and it is compared with the other metrics. This thesis was supported by a TUBITAK project titled "Reliable Microprocessor Design" under grant number 112E004.