Memory Testing

Memory TESTING

Vannapha Phommathansy Yi Lan Suhas Shanker Prodduturi Prashant Tripathi Balaji Panda

Agenda 1. Brief overview of Memory 2. Fault type , Fault modeling

3. 5. 6. 7.

Discuss FuncEonal fault and Reduce FF Coupling fault Address decoder fault March test Algorithm

8. Conclusion 9. Q&A

Overview of Memory

ü Memory is the most dense physical structure ü Considering the increase density, memory arrays are more sensiEve to defects

DRAM FLASH Semiconductor memory

SRAM

ROM

CDRAM

Test Eme in Sec VS size n bit

Fault Types

1. Permanent: can’t be model , system is broken and fault exist indefinitely 2. Transient: non permanent cause by environmental condiEon can be fix 3. Intermi\ent: caused by non environmental condiEon, occur randomly.

Fault Modeling

Ø Behavior Ø FuncEonal Ø Logic Gate Ø Electrical Ø Geometrical

² Simplified ² Reduce funcEonal test ² Subset funcEonal test

FuncEonal Memory Model

Reduce funcEonal fault

SAF – Stuck at fault TF – TransiEon fault CF -­‐ coupling Fault Address Decoder Fault 1. CF Inversion 2. CF Idempotent 3. Bridging Fault 4. Dynamic fault 5. State Coupling 6. NPSF -­‐