HOME TASK 3 - Dummy RISC & CISC

HOME TASK 3

READ THE WHOLE TASK AND GUIDELINES BEFORE YOU START WITH YOUR HOME TASK. READ EACH PART BEFORE YOU START WORKING ON IT.

Download the HomeTask3_RISCvsCISC.xlsx file that is attached to this task. Read the description of the Task carefully and complete the tables in the document. 

HOME TASK 3 is divided into 2 parts as follows:

Part 1 - Both groups must complete this part

In this part, we will assume that the 8-bit Dummy CPU is designed as CISC and RISC architectures.
You are required to produce two performance equations, using the performance equation we discussed in class:

You will be using the execution trace you produced for program 1 in your HOME TASK 2.

1- The first equation will be performance evaluation for program 1 if it was executed on a CISC-based  8-bit Dummy CPU.
1- The second equation will be performance evaluation for program 1 if it was executed on a RISC-based  8-bit Dummy CPU.

The parameters that you should use are as follows:
1- The number of cycles per instruction for both RISC and CISC is sown in Table 1.
2- In CISC, one cycle takes 1.45 nanoseconds to complete.
3- In RISC, one cycle takes 1.12 nanosecond to complete.

Use the execution trace^* you produced last week in HOME TASK 2 to figure out how many times each instruction was used during the execution. Be careful! Some instructions can take more time than others. You need to account to different timings that different instructions may need to finish. Table one and parameters 2 and 3 should help you with that.

*All instructions in the trace must be accounted for in the performance evaluation. The performance evaluation must include the entirety of the execution period.

Table 1

Operation	use	# of cycles in RISC	# of cycles in CISC
LD	LD #5	1	0.8
	LD $5	2	1
ST	ST #2	1	0.8
	ST $2	1	1
ADD	ADD #10	1	1
	ADD $10	2	1.4
SUB	SUB #4	1	1
	SUB $4	2	1.4
EQ	EQ #5	1	1
JP	JP $8	1	0.8
HE	HE	1	0.5

Part 2 - Only for IASM group1

As you may have noticed, most instructions take a different number of cycles to finish executing when executed using RISC vs. when executed using CISC. What is the effect of that difference in performance?
To answer this question, I want you to take 2 example instructions: ADD $10 and JP $8. Compare their timing when executed in RISC vs. when executed in CISC.
What does that mean for the performance evaluation? What do you conclude from that comparison?

Guidelines

1. Fill the HomeTask3_RISCvsCISC.xlsx with your name and student code on the first page. You can add your name to the name of the File.
2. DO NOT FORGET TO CLICK THE SUBMIT BUTTON WHEN YOU FINISH YOUR ANSWERS. OTHERWISE, I WILL NOT SEE YOUR ANSWERS.

If you have any questions, please post them on the Course participant's forum (ask questions from a teacher/other participants). Other students are encouraged to participate in asking and answering questions.