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Power Studies

Study Results

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.

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.

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.

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.

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.

Power Measurment Graphs

Table Summary Results
JPower Slopes 5.30 30.51 48.04
XPower Slopes 5.28 30.77 50.12
JPower TMR vs. Non-TMR Ratio 3.50 3.88 4.29
XPower TMR vs. Non-TMR Ratio 3.44 3.87 5.37
Size (LUTs) 1728 9750 19968

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