Simple Introduction Pipeline

 

Note: 1 is quasi-parallel, not real parallel.2. The pipeline improves the utilization of components and the average execution speed of commands,Speed of executing a single commandNoImprove.

The features of assembly line commands: the commands executed by the assembly line are the same operation commands, and they can be divided into several identical steps.

It can be clearly seen that, without using the pipeline, the blue blank devices between the three commands are all idle, and the time is wasted.

After the assembly line is adopted, the time used is shortened from 9 t to 5 T, saving one half of the time. It greatly improves the device utilization and shortens the overall time, but the time for executing a single command is still 3 TB. Because the pipeline cannot change the time of a single command.

Here, △tj is the pipeline cycle.

This is the formula used to calculate the pipeline running time. It looks complicated and simple. That is, the execution time + (number of command lines-1) × pipeline cycle. Another calculation method is to use the number of segments divided by a command.× Pipeline cycle +(Command lines-1)× Pipeline cycle. when a question is generally used in a soft exam, the formula is used first. If the option is not used, the second method is used. The two calculation results are not displayed in the options.

The second method regards the execution time of each instruction period as the pipeline cycle for calculation. It can be viewed as a rough calculation method.

The formula method is used to calculate the specific time of each period, which is more accurate than the second method. Therefore, the formula is used by default.

Once you understand these pipelines, it will solve the problem. What other throughput and acceleration ratio is too simple. I will not go into detail here.