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cpuclockcyclefrequencypipeline

Pipeline Processor Calculation

My assignment deals with calculations of pipelined CPU and single cycle CPU clock rates.

The following data is given, about the time each operation takes to execute:

IF:400 PS
ID:100 PS
EX:350 PS 
MEM:700 PS
WB:100 PS

A. What is the clock frequency if the CPU works as a single cycle? How long does it take to execute a single operation?
B. What is the clock frequency if the CPU works as a Pipelines CPU? How long does it take to execute a single operation?

I know that for A a single operation takes 1650 ps to execute because in a single cycle CPU we have to perform every stage to execute a single operation. What I don't understand is why is the frequency 0.606?

For B, I know that to execute we have 700 Ps, because a pipelined CPU takes to longest stage as the CPU as the time. What I don't know, is what is the answer to the frequency question?

Any help is blessed.

Solution

  • Well frequency is the reciprocal of time, so:

    1 / 1650 ps = 606 MHz = 0.606 GHz

    and

    1 / 700 ps = 1429 MHz = 1.429 GHz

    Note that the prefix p stands for pico, which is a multiplier of 10-12. So one picosecond (ps) is equal to 10-12 = 0.000000000001 seconds.