Hi,

 

Can anyone explain to me how to do pipeline diagrams?

 

Here's an example of an exam question:

 

 

 

 

I don't just want the answer to this question, if someone could help explain to me how to do it that would be great!!

Hi harry,

 

Are you familiar with the 5-stage pipeline which is what in the question here?

If you are and you know about what each stage do, then this should be an easy task.

 

I have illustrated here a simple operation as a pipeline diagram.

 

A = B + C

 

First try converting your operation as assembly instructions.

As assembly instructions, the above operation can be represented as ( I am using load-store architecture)

 

LD R1,B

LD R2,C

ADD R3,R1,R2

SD A,R3

 

( All variables are in-fact memory locations).

 

Your pipeline diagram is shown.

 

Note:

 

1. This is the basic execution flow. I have not used bypassing or forwarding here. You must use it in your implementation.

2. As you will see , that even after implementing forwarding, some stalls will still occur. At this point, you can use the independent instructions from your other operation instead of waiting for the stall. Like, you can insert the load operations of your other operation after the load instructions of first operation, so that processor doesn't sit idle.

3. While doing this, you must keep in mind that the program order must be preserved.

 

Hope this helps.

I have been very vague. Ask in case of any concern!

 

 

Hi,

 

Can anyone explain to me how to do pipeline diagrams?

 

Here's an example of an exam question:

 

 

 

 

I don't just want the answer to this question, if someone could help explain to me how to do it that would be great!!

 

pipeline_diagram.bmp

 

Sorry, forgot to attach the diagram in my reply.