1. Partially Protected Caches to Reduce Failures Due to Soft Errors in Multimedia Applications
Kyoungwoo Lee, Aviral Shrivastava, Ilya Issenin, Nikil Dutt, and Nalini Venkatasubramanian
IEEE TRANSACTIONS ON VERY LARGE SCALE INTEGRATION (VLSI) SYSTEM
Dohwan Kim

2. Table of contents Soft error
Failure noncritical (FNC) and failure critical (FC)
Partially protected cache (PPC)
Design space exploration (DSE) algorithm
Conclusion

3. Soft error
A high-energy radiation particle may strike the diffusion region of a complementary metal-oxide- semiconductor transistor.
This phenomenon changes the logic state of a transistor.
Soft error is not repeatable error.

4. FNC and FC In multimedia applications
Failure noncritical (FNC) data: the image data or audio data
Failure critical (FC) data: the loop variable or the stack pointer

5. FNC and FC
A cache miss, generally, is when something is looked up in the cache and is not found.

6. PPC Partially protected cache architecture Unprotected cache -> FNC
Protected cache -> FC
Increased transistor size, increased supply voltage, SEC- DED, etc

7. PPC
It is important to choose the best configuration of a PPC to satisfy multiple design constraints such as the failure rate, power, and performance.
Size of protected cache ↑ -> failure rate ↑ cache miss rate ↓
Set associativities ↑ -> performance ↑ energy consumption ↑

8. DSE algorithm BFExplore algorithm
S: a set of sizes of the protected cache
A: a set of set-associativity from 1-way to 32-way
Constraints: runtime and energy consumption

9. DSE algorithm
BFExplore algorithm

10. DSE algorithm BRExplore algorithm
S: a set of sizes of the protected cache
A: a set of set-associativity from 1-way to 32-way
Constraints: failure rate and energy consumption

11. DSE algorithm
BRExplore algorithm

12. Conclusion
They propose PPC which can mitigate failures caused by soft errors in multimedia embedded applications.
They also propose heuristic algorithms, BFExplore and BRExplore, to efficiently find the best configuration for proposed PPC architectures.