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(a) What is the cycle time that maximizes performance without allocating multiple cycles to a segment? |
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(b) What is the total time to execute the function (through all stages)? |
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(c) What is the cycle time that maximizes performance if each segment can be partitioned into sub-segments? |
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2. Repeat problem 1 if there is a 1 ns clock skew (uncertainty of ±1 ns) in the arrival of each clock pulse. |
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3. A four-segment pipeline to execute a function has the following parameters: |
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| Segment # | Pmax | Pmin | | 1 | 14 | 7ns | | 2 | 12 | 9ns | | 3 | 16 | 10ns | | 4 | 11 | 5ns |
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The clock overhead, C, for each register stage is 3ns. |
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(a) If no controlled clock skew is allowed, what is the latency of execution (through all stages) for the function? What is the minimum cycle time? |
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(b) If we now allow controlled clock skew to take advantage of Pmin what is the latency, minimum cycle time, and clock skew required at each stage? |
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4. Repeat problem 3 if there is an additional 1 ns of uncertainty in the arrival of the clock at each segment. |
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5. Plot Soptwith respect to clock skew factor (k) for k = 0.05 to k = 0.20. Assume T = 120ns, C = 5ns, and b = 0.2. |
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6. We can generalize the equation for Sopt/sub> by allowing for pipeline interruption delay of S -a cycles (rather than S - 1), where S >a ³ 1. Find the new expression for Sopt. |
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7. (a) Show that the effect of uncontrolled clock skew(±d) in a regular pipeline is to increase C, and hence cycle time, by 2d. |
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(b) Show that the effect of uncontrolled clock skew (±d) in a wave pipeline is to increase C, and hence cycle time, by 4d. |
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8. Repeat Study 2.1, with the delay in R®ALU®R = 16 ns and instruction and data cache data access = 8ns. |
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9. Acertain pipeline has the following functions and functional unit delays (without clocking overhead): |
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