By Paul N.Whatmough , Shidhartha Das, David M,Bull ARM, Cambridge, United Kingdom
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Transcript of By Paul N.Whatmough , Shidhartha Das, David M,Bull ARM, Cambridge, United Kingdom
Class presentation based on ISSCC 2013- 24.5 :
A Low-power 1GHz Razor FIR Accelerator with Time-Borrow Tracking Pipeline and Approximate Error Correction in 65nm CMOSBy Paul N.Whatmough, Shidhartha Das, David M,BullARM, Cambridge, United Kingdom
Presented by:1Mahnaz Rasti1Department of Electrical and Computer Engineering, University of Tehran, Tehran, Iran
Spring 2013
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Outline:• Razor Systems• ANT(Algorithmic Noise Tolerance) Circuits• Combining Technologies• Architecture of the Chip
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Outline:• Razor Systems• ANT(Algorithmic Noise Tolerance) Circuits• Combining Technologies• Architecture of the Chip
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Razor Systems:One of the more effective and widely used methods for power aware computing is:
DVS (Dynamic Voltage Scaling)
Voltage
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Razor Systems:• Razor propose a new approach to DVS, based
on dynamic detection of circuit timing errors
• Key Idea:
Tune the supply voltage by monitoring the error rate during circuit operations[1]
[1( ]MICRO-36 ,)December 2003 - Razor: A Low-Power Pipeline Based on Circuit-Level Timing Speculation- Dan Ernst
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Razor Systems(ex. flip-flop[1])
• Double samples pipeline stages value• Once with a fast clock• Again with a time borrowing delay clock
• A metastability-tolerant comparator then validates latch value sampled with fast clock• In the case of a timing error, a modified pipeline
mispeculation recovery mechanism restores correct program state.
[1 ]Ref: (MICRO-36), December 2003 - Razor: A Low-Power Pipeline Based on Circuit-Level Timing Speculation- Dan Ernst
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Razor Systems:
Figure 1. Pipeline augmented with Razor latches and control lines.Ref:(MICRO-36), December 2003 - Razor: A Low-Power Pipeline Based on Circuit-Level Timing Speculation- Dan Ernst
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Outline:• Razor Systems• ANT(Algorithmic Noise Tolerance) Circuits• Combining technologies• Architecture of the Chip
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ANT Circuits:
Figure 2 Ref: http://icims.csl.uiuc.edu/~vips 9
ANT Circuits:• Modify algorithm for system level error control
• ANT detects such errors in system output and mitigates their effects on system performance.
• Errors are detected by low complexity prediction scheme.
Figure 3 Ref:http://icims.csl.uiuc.edu/~vips
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ANT Circuits:
Figure 4 : Error predictor in ANT Circuits-[http://icims.csl.uiuc.edu/~vips]
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Outline:• Razor Systems• ANT(Algorithmic Noise Tolerance) Circuits• Combining technologies• Architecture of the Chip
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:Combining technologies
Razor SystemsLow power, fault tolerant
•ANT•Rely on imbalance ripple adder
and hence limited clock frequency, increasing baseline
area and power
&High clock frequencyLow overheads
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Outline:• Razor Systems• ANT(Algorithmic Noise Tolerance) Circuits• Combining technologies• Architecture of the Chip
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Architecture of the Chip
Approximate Error Correction
Time Borrow Tracking
Figure5: FIR accelerator with Razor latches, time-borrow tracking (TBT) and approximate error correction (AEC)- ISSCC 2013 – 24.5
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Architecture of the Chip
Figure6: FIR accelerator with Razor latches, time-borrow tracking (TBT) and approximate error correction (AEC)- ISSCC 2013 – 24.5
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Characteristics:• Tow distinct error correction technique • TBT• AEC
• A 1Ghz datapath due to elimination of ripple-carry adders
• Energy efficiency improvement of up to 37%
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Die:TSMC CMOS 65nm LP Technology Node
530 micron * 350 micron Dimension
16-Tap FIR, 8b coefficient , 18b o/p Pipeline Design
1974(393 in pipeline /)120 (30% of pipeline FF)
Total FF/RZL
1.59% Hold Buffer Area Overhead
1.008 GHz @ 1.2v with Razor Max Clock Frequency
Figure7: Die photo- ISSCC 2013 – 24.5
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References: 1. ISSCC 2013 – 24.5 – “A Low-Power 1GHz Razor FIR Accelerator with
Time-Borrow Tracking Pipeline and Approximate Error Correction in 65nm CMOS” - Paul N. Whatmough - ARM, Cambridge, United Kingdom.
2. (MICRO-36), December 2003 – “Razor: A Low-Power Pipeline Based on Circuit-Level Timing Speculation”- Dan Ernst
3. “Algorithmic Noise Tolerance for Low Power Signal Processing in the Deep SubMicron Area” - ECE Department University of Illinois at Urbana-Champaign
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