5.3.2. Fault Coverage with Scan Chains

Try these first

1. 1.

   What is a stuck-at fault?

   Hint

   Think about how circuits behave normally.

2. 2.

   How do scan chains help detect faults?

   Hint

   Consider both observability and controllability.

3. 3.

   What type of fault occurs when a node is stuck at a logical high or low?

   • Delay Fault
   • Stuck-At Fault
   • Bridging Fault

   Hint

   Remember the definition of stuck-at faults.

4. 4.

   True or False: Scan chains can completely eliminate all types of faults.

   • True
   • False

   Hint

   Consider the limitations discussed.

5. 5.

   Design a circuit that could potentially include stuck-at faults and outline a testing strategy using scan chains.

   Hint

   Think about handling each node in your test design.

6. 6.

   Consider a complex IC that implemented scan chains. Discuss the potential consequences if delay faults are overlooked during testing.

   Hint

   Reflect on what timing inconsistencies could lead to in synchronous systems.