CS 2731 Recitation 9

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CS 2733/2731
Computer Organization II
Fall 2004
Recitation 9
addi in single- / multi-cycle
    Week 9: Oct 18-22
Due (on time): 2004-10-27  23:59:59
Due (late):        2004-10-31  23:59:59

Recitation 9 must be submitted following directions at: submissions on or before

2004-10-27 23:59:59 (that's Wednesday, 27 October 2004, 11:59:59 pm) for full credit.
2004-10-31 23:59:59 (that's Sunday, 31 October 2004, 11:59:59 pm) for 75% credit.

Outline: This recitation studies the addi instruction in both the single-cycle and multi-cycle implementation. In summary, you are to create a data path diagram showing how the addi instruction can be carried out in each of these two implementations. Your diagrams should be similar to those given out in class. (Diagramming the instruction for the single-cycle model is an exercise in your text.) It is interesting (and it's a big hint), that no real additional control or data lines are needed for the implementations.

Specifics about the instruction: Assume for both the single- and multi-cycle model that the instruction is the following instruction: addi $t3, $t2, 45

Instruction: `addi $t3, $t2, 45`
214b002d				(in hexadecimal)
001000	01010	01011	0000000000101101	(fields in binary)
8	10	11	45	(fields in decimal)

In marking the values traveling along data lines, assume that $t2 = $10 holds the value 51 and that $t3 = $11. (Note that the ALUOp control can be two 0 bits, so that the input to the ALU from ALU control will then be 010, that is, an add.)

Details of implementing addi in the single-cycle model: This is Exercise 5.19 on the CD, under the category "For More Practice". You can use your own xerox of the diagram in Figure 5.17 (or Figure 5.24 that includes everything), or you can use one of the single-cycle worksheets from the previous edition that I am passing out (2nd Ed., Figure 5.29). You should show the new control settings on the same worksheet. Thus for this part you should hand in a single worksheet.

Details of implementing addi in the multi-cycle model: This is similar to the previous item, except that it uses the multi-cycle implementation. You can use your own xeroxes of the diagram in Figure 5.28, or you can use one of the multi-cycle worksheets from the previous edition that I will be passing out (2nd Ed., Figure 5.33). You should show the modifications to the finte state machine control given in Figure 5.38. You can write this on the back of one of the worksheets. Thus for this part you should hand in one or more worksheets, depending on how many cycles you show together on the same worksheet.

What you should submit: Refer to the submissions directions and to deadlines at the top of this page. The text file that you submit should first have Your Name, the Course Number, and the Recitation Number. The rest of the file should have the following in it, in the order below, and clearly labeled, including at the beginning the appropriate number 1-2.

Contents of submission for Recitation 9:
Last Name, First Name; Course Number; Recitation Number (9).

By the usual online method, you must submit a brief description of how the addi instruction is handled in each implementation.

For the single-cycle implementation, this should include the relevant control signals, and an outline of the actions taken.
For the multi-cycle implementation, this should include a description of the actions during each cycle, similar to Figure 5.30 on page 329, and a description of the necessary new control states and their control values, that would fit into Figure 5.38 (but just a text listing and not a diagram).

Separately, for full credit, you must submit the diagrams as actual sheets of paper, on or before class on Friday, 29 October 2004.

Revision date: 2004-06-27. (Please use ISO 8601, the International Standard.)