Virtual Labs

Experiment name

What is the key role of the scoreboard in dynamic scheduling?

a: Detecting and eliminating compiler errors Explanation

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b: Enabling parallelism by statically reordering instructions Explanation

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c: Dynamically tracking instruction states and dependencies Explanation

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d: Compressing instruction sequences for efficiency Explanation

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Compared to static scheduling, scoreboarding allows:

a: Out-of-order issue and in-order write Explanation

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b: In-order issue and out-of-order completion Explanation

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c: Full out-of-order execution with hazard control Explanation

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d: Instruction speculation Explanation

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Which of the following must be true before the 'Read Operands' stage begins for an instruction?

a: Functional unit must be free Explanation

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b: Destination register must be locked Explanation

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c: All source operands must be available Explanation

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d: All previous instructions must have completed Explanation

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In scoreboarding, the Issue stage is blocked when:

a: All source operands are not ready Explanation

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b: The instruction has a RAW dependency Explanation

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c: The functional unit is busy or WAW hazard exists Explanation

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d: The instruction is already in the scoreboard Explanation

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A 'Write Result' stage must be delayed if:

a: Another instruction has already written to the same register Explanation

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b: Another instruction is scheduled to write to the same register Explanation

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c: The functional unit is still busy Explanation

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d: The operands are not yet fetched Explanation

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What causes a structural hazard in a scoreboard-based system?

a: Multiple instructions writing to the same register Explanation

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b: Functional unit unavailable when instruction is ready to issue Explanation

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c: Reading operands too early Explanation

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d: All instructions depending on the same source Explanation

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Which of the following is true under scoreboarding? I1: DIV F2, F4, F6 I2: ADD F0, F2, F8 I3: SUB F4, F0, F10

a: I2 and I3 execute in order without stalls Explanation

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b: I2 stalls at Read Operands due to RAW Explanation

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c: I3 causes a WAW hazard with I1 Explanation

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d: I2 is blocked due to structural hazard Explanation

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A student clicks 'Write Result' for an instruction, but it's blocked. Why?

a: The instruction has not been issued Explanation

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b: A WAR hazard exists with an instruction not yet in Write Result Explanation

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c: A RAW hazard is pending Explanation

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d: The register is empty Explanation

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Which of the following best differentiates scoreboarding from Tomasulo’s algorithm?

a: Scoreboarding tracks register readiness with tags Explanation

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b: Tomasulo’s algorithm uses a centralized scoreboard Explanation

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c: Scoreboarding uses register renaming to eliminate WAR/WAW Explanation

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d: Tomasulo uses register renaming; scoreboarding does not Explanation

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