electronic engineering Electronics engineering is a sub-discipline of electrical engineering which emerged in the early 20th century and is distinguished by the additional use of active components such as semiconductor devices to amplify and control electric current ...

, a bridging fault consists of two signals that are connected when they should not be. Depending on the logic circuitry employed, this may result in a

wired-OR A wired logic connection is a logic gate that implements boolean algebra (logic) using only passive components such as diodes and resistors. A wired logic connection can create an AND or an OR gate. The limitations are the inability to create a ...

wired-AND A wired logic connection is a logic gate that implements boolean algebra (logic) using only passive components such as diodes and resistors. A wired logic connection can create an AND gate, AND or an OR gate. The limitations are the inability t ...

logic function. Since there are O(n^2) potential bridging faults, they are normally restricted to signals that are physically adjacent in the design.

Modeling bridge fault

Bridging to VDD or Vss is equivalent to stuck at fault model. Traditionally bridged signals were modeled with logic AND or OR of signals. If one driver dominates the other driver in a bridging situation, the dominant driver forces the logic to the other one, in such case a ''dominant bridging fault'' is used. To better reflect the reality of CMOS VLSI devices, a ''dominant AND or dominant OR bridging fault model'' is used where dominant driver keeps its value, while the other signal value is the result of AND (or OR) of its own value with the dominant driver.

References

"Bridging Fault Model"
from ''Test and Diagnosis for Small-Delay Defects''
"Bridging Fault"
from ''Integrated circuit test engineering: modern techniques''
"A bridging fault model where undetectable faults imply logic redundancy"
from '' Design Automation and Test in Europe'' Electronic engineering