Power Reduction Technique

1
Power Reduction Technique

• Parallelism in circuits using duplication of
  logic

2
OUTLINE

• Problem Definition
• Steps for Implementation
• Background Information
• Experimental Results
• Theoretical Results
• Conclusion
• Lessons

3
Problem Definition

• Design a 32 bit adder with parallelism
• Operational speed must be the same (throughput
  constant)
• Show it to be an effective Power reduction scheme

4
Block diagram Representation
5
Implementation Technique

• MODELSim, Leonardo, Design Architect, Eldo
• Technology used ami 0.5
• Delay calculation( 50 of the rise time)
• VHDL/Verilog
• http//www.amis.com/pdf/process_specifications/c5_
  ss.pdf

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Power versus voltage (N1)
Voltage Dynamic Power (mW) Static Power (uW)
5 22.4128 33.471
4 13.1289 21.020
3 7.9665 11.658
2 3.7048 5.114
1 0.5181 1.256
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Dynamic Power v/s Voltage (N1)
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Power versus voltage (N2)
Voltage Dynamic Power (mW) Static Power (uW)
3.5 18.095 56.18
3 12.775 48.11
2.5 9.0875 34.62
2 6.0511 22.01
1.5 2.2306 14.32
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Dynamic Power v/s Voltage (N2)
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Delay versus Voltage (N1)
Voltage (Volts) Delay (Nano secs)
5 0.34
4 0.41
3 0.608
2 1.01
1 3.77
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Delay versus Voltage (N1)
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Experimental Results
Delay (nS) Voltage (N1) Voltage (N2)
0.34 5 3
0.41 4 2.5
0.608 3 1.5
1.01 2 NA
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Power Reductions
Reference voltage (V) Power (mW) (N1) Voltage (V) Power (mW) (N2) Reduction
5 22.41 3 12.77 42.99
4 13.12 2.0 6.051 53.39
3 7.995 1.5 2.2306 72.17
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Theoretical Calculations

• Power CVDD2
• The Delay versus Voltage graph can be used for
  interpolating the voltage levels for various
  degrees of parallelism

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Theoretical v/s Experimental
Voltage (Reference) V Theoretical Value (V) Experimental Value (V) Power Reduction (Theoretical) Power Reduction (Experimental)
5 3.2 3 52.40 42.99
4 2.3 2.5 64.60 53.39
3 1.4 1.5 78.12 72.17
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Conclusions

• Parallelism is an effective power reduction
  technique
• However, it causes extra designing effort
• The theoretical calculations do not exactly match
  because the overhead hasnt been taken into
  account in it

17
Lessons

• Patience!!!!!!!!!!!!!!!!!!!!!!!!!

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References

• Dr Agrawals website
• Mentor manuals

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• Thank You!!!!!