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Study Results |
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The results of the two different power measurement tools are presented here. Along
with callibration results, we discover the power costs of TMR. It is also interesting
to note how sensitive power measurments are to design placement. Different placements
of each incrementer and counter design are used to emphasize this sensitivity.
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In the results that follow, both the JPower and XPower tools were used to measure the
power of a design at frequencies ranging from 10 MHz to 70 MHz. The results of these measurements
are plotted in the graphs that follow. In each graph will usually be two pairs of
results. The lower red and blue line are the results for the design without the use of
TMR and the top red and blue lines are the results with TMR. All blue lines correspond to
JPower results, while all red lines correspond to XPower results.
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Also included in the following results are tables which summarize important information for
each design. One of the pieces of information summarized is the slope of each line in the
graphs. This slope reports the increase in mA per 1 MHz for a given design. Another important
result is the TMR vs. non-TMR power ratio for a given design.
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The following results are available: |
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3CLK Results
Previous TMR studies done at LANL indicate that a triplicated clock domain is important
for complete SEU immunity. Unfortunately the SLAAC-1V board does not make clock triplication
easy. There are not three global clock pins reserved on the board by default. For this reason
clock skew is a problem for three identical clock signals on the SLAAC-1V board. This means
that power measurments will not be completely accurate. The effects of placement were not studied
with triplicated clocks.
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Unlike previous graphs, there are three pairs of lines on the following graph. The bottom pair
correspond to the incrementer design with TMR and triplicated clocks. The middle pair corresopond
to the XOR'ed incrementer design with TMR and triplicated clocks and the top pair correpond to the
counter design with TMR and triplicated clocks.
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Power Measurment Graphs
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Table Summary Results
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