CS33 -- Lab 3

email to me at: cfk@cs.swarthmore.edu a message in text form (no word, html or any other format than plain text) that contains labeled solutions to the exercises below. Make the subject of the email: cs33lab3. Make sure it is posted to me before 11:59 pm on Thursday, 16 Sep. Some of the solutions will just be binary, hex, or decimal. Others may require prose explanations.

For this lab assignment, feel free to work with a partner.

Complete the following exercises from the textbook:

1. 3.34
2. 4.1
3. 4.5
4. 4.8
5. 4.12 (with P&P phases)
6. 5.4
7. 5.8
8. 5.12
9. 5.14
10. 5.15
11. In class, we will write (or did write, depending on when you read this) a little LC3 machine language program to add the contents of memory location x3020 to the contents of memory loc x3021 and put the result into memory loc x3022. We used R4 as a base register and put x3020 into R4 before executing our instructions The program looked like: ;; before executing this program, put x3020 in R4 loc instruction comment x3004 x6700 ;; R3 <-- M[R4+0] x3005 x6501 ;; R2 <-- M[R4+1] x3006 x1083 ;; R0 <-- R2+R3 x3007 x7102 ;; M[R4+2] <-- R0 I want you to write an LC3 machine language program that subtracts the contents of memory loc x3021 from the contents of memloc x3020 and puts the difference in memloc x3022. Present it with comments as in my little adding example above.
    Hint: The LC3 does not have a subtract instruction, nor does it have a 2's complement instruction. It does, however, have a not and the ability to add 1, so your program can compute the 2's complement of the subtrahend and then use the ordinary add to get the difference in a register.