1 / 25

Efficient Storage of Defect Maps for Nanoscale Memory

Efficient Storage of Defect Maps for Nanoscale Memory. Susmit Biswas Tzvetan S. Metodi* Frederic T. Chong Ryan Kastner Tim Sherwood {susmit,chong,sherwood}@cs.ucsb.edu, kastner@ece.ucsb.edu, tsmetodiev@ucdavis.edu. *. Nanotechnology in Action. Scaling limit of CMOS Vdd ~ 1V Leakage

ronny
Download Presentation

Efficient Storage of Defect Maps for Nanoscale Memory

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Efficient Storage of Defect Maps for Nanoscale Memory Susmit Biswas Tzvetan S. Metodi* Frederic T. Chong Ryan Kastner Tim Sherwood {susmit,chong,sherwood}@cs.ucsb.edu, kastner@ece.ucsb.edu, tsmetodiev@ucdavis.edu *

  2. Nanotechnology in Action • Scaling limit of CMOS • Vdd ~ 1V • Leakage • Design of new nanoscale devices • SONOS, CMOL, Crossbar memories • CNT interconnect

  3. Nanotechnology: Pros and Cons • Higher Density • 5nm<=Fnano <= 10nm • Faster operation • Fast switching • Low active power • Inexpensive • Reliability • Manufacturing defects might be as high as 10% [DeHon-NanoTech2005]

  4. Solution: Reconfiguration • Dynamic • High latency in testing • Static: Defect Map • Using bit-level reconfiguration • High overhead in storage • Block level reconfiguration Efficient storage techniques !

  5. Presentation overview • Motivation • Prior Work • Our Approach • Algorithms • Results • Conclusion

  6. Prior Work • 1D list of regions [sun-NanoArch-06] • Bloom filter defect map [Wang-ICCAD2006]

  7. Example: A Defective Memory

  8. Map of good regions • List based approach • Ranges • 1D • 2D • Can be stored in TCAM • Good for correlated defects

  9. Storing Defect Map in Rectangles

  10. Equivalent Problem:Finding optimal rectangle cover • NP-Complete problem • Greedy Algorithm • R-Tree as data structure • New point inserted greedily for least increase in rectangle area • Suitable for storing ranges • k-means clustering to decide the insertion order of points

  11. Algorithm

  12. 6 R4 3 1 R5 8 R2 R1 R6 7 5 2 R3 4 Algorithm 1: Illustration Root R1 R2 R5 R3 R6 R4

  13. Storing Sparse Defect Locations • Bloom filter defect map [Wang-ICCAD2006] • Supports membership queries • Uniform hash function • No false negative • False positive • Better storage efficiency than bit vector D={d1, d2,…, dn} H1(d1) H2 (d1) H3 (d1) H4 (d1)

  14. Bloom filter as Defect Map

  15. Combined Approach

  16. Combined Approach

  17. 6 R4 3 1 R5 8 R2 R1 R6 7 5 2 R3 4 Algorithm 2: Illustration Root R1 R2 R3 R4

  18. Distribution of density

  19. Improvement in distribution

  20. Experiments • Error Model • Gaussian distribution • Test data • Synthetic • TCAM: 128 Entry • Bloom filter: 5 times number of points

  21. Results

  22. Coverage of Errors

  23. Conclusion • Defect map storage techniques • Region based • Combined approach with Bloom filter • Error model • Need of Finer model

  24. Questions? Thanks!

  25. References [sun-NanoArch-06] “Two Fault Tolerance Design Approaches for Hybrid CMOS / Nanodevice Digital Memories”,Fei Sun and Tong Zhang, NanoArch ’06 [Wang-ICCAD2006]“On The Use of Bloom Filters for Defect Maps in Nanocomputing”, Gang Wang, Wenrui Gong, Ryan Kastner, ICCAD ’06 [DeHon-NanoTech2005]“Non-Photolithographic Nanoscale Memory Density Prospects”, André DeHon, Seth Copen Goldstein, Philip J. Kuekes, and Patrick Lincoln, IEEE Tr. Nanotechnology ’05 [Nicolaidis-JET2005] “Memory Defect Tolerance Architectures for Nanotechnologies”,Michael Nicolaidis, Lorena Anghel, Nadir Achouri, Journal of El. Test. 2005

More Related