1 Class Presentation For Advanced VLSI Course Professor: Dr. S. M. Fakhraie Presented by: Sayyed Hassan Sohofi Major Reference: A 0.13µm Triple-Vt 9MB Third Level On-Die Cache for the Itanium ® 2 Processor By: Jonathan Chang, Jonathan Shoemaker, Mizan Haque, Ming Huang, Kevin Truong, Mesbah Karim, Siufu Chiu, Gloria Leong, Kiran Desai, Richard Goe, Sandhya Kulkarni, Arun Rao, Daniel Hannoun, Stefan Rusu Intel Corporation, Santa Clara, CA In: 2004 IEEE International Solid-State Circuits Conference Winter 2004

2 Outline  Processor highlights  Itanium® processor evolution  Itanium ® 2 Architecture  Cache Hierarchy  L3 cache trends  9MB cache organization  Stage mode ECC logic  Frequency shmoo  Summary  References

[1]3 Itanium ® 2 Processor 9M Highlights  592M transistor  432mm 2 die size  9MB on-die L3 cache  1.7GHz at 1.35V  6.4GB/s 400MT/s 4- way bus interface  Read and write bandwidth 54 GB/s  EPIC Architecture  4-port cache memory  For Technical and Commercial Servers

[1]4 Itanium ® Processor Evolution

5 Itanium ® 2 Architecture [2]

6 Itanium ® 2 Architecture [4]

7 Cache Concepts  Terminology ● Hit: data appears in some block in the upper level ● Miss: data needs to be retrieve from a block in the lower level  Block placement ● Direct map ● Fully Associative ● Set Associative  Block replacement ● Random ● FIFO ● LRU ● NRU ● LFU  Write strategy ● Write through ● Write back

[3]8 Set Associative Mapped Cache

[4]9 Cache Hierarchy

[2]10 Cache Hierarchy

[2]11 Hit Detection

[1]12 L3 Cache Trends

13 L3 Subarray Subarray Size: 2 * 8 * (96*256) = 48 KB [1]

14 Cache Organization 96*256

15 Group Extension for 9M Data-group [1]

16 Stage Mode Logic  Maintain 4-cycle tag look-up when no ECC error occurs  Re-circulate the request and perform in-line ECC error correction when detecting an ECC error with one additional cycle  Can permanently set tag look-up to 5-cycle if desired  Special logic handling and mutually-exclusive guarantee circuitry added for false hit and dummy read [1]

17 Stage Mode Logic [1]

18 L3 Behavior with ECC Errors [1]

19 L3 Behavior with ECC Errors [1]

20 L3 Behavior with ECC Errors [1]

21 L3 Behavior with ECC Errors [1]

22 L3 Behavior with ECC Errors [1]

23 Infrared Emission Photo [1]

24 Frequency Shmoo [1]

25 Summary  Itanium® is a processor for technical and commercial servers applications  Itanium® 2 Processor 9M has the largest on-die cache and transistor count reported for a processor  Modular cache extension methodology enables reuse of existing subarray and floorplan  Three-Level cache for satisfying technical and commercial applications  50 bit of physical address to provide 1024 Tbyte of addressability  Stage mode ECC logic maintains existing latency and adds one extra cycle only for ECC correction events  Best performance at 1.7GHz and 1.35V

26 References [1] Jonathan Chang, Jonathan Shoemaker, Mizan Haque, Ming Huang, Kevin Truong, Mesbah Karim, Siufu Chiu, Gloria Leong, Kiran Desai, Richard Goe, Sandhya Kulkarni, Arun Rao, Daniel Hannoun, Stefan Rusu, “ A 0.13µm Triple- Vt 9MB Third Level On-Die Cache for the Itanium ® 2 Processor” ISSCC 2004 Conference [2] Cameron McNairy,Don Soltis ”ITANIUM 2 PROCESSOR MICROARCHITECTURE” IEEE Computer Society MARCH–APRIL 2003 PP [3] John Hennessy, David A. Patterson “Computer Architecture: A Quantitative Approach” 2003 Edition [4] Stefan Rusu, Harry Muljono, Brian Cherkauer “ITANIUM 2 PROCESSOR 6M: HIGHER FREQUENCY AND LARGER L3 CACHE” Computer Society MARCH–APRIL 2004 PP [5]J. Stinson, S. Rusu, “A 1.5GHz Third Generation Itanium® Processor” ISSCC Dig. Tech. Papers, pp , Feb