Pipeline Processor Calculation

1
votes

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.

1
cpuclockcyclefrequencypipeline

1 Answers

4
votes

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.