Assignment 3, due Sep 12

STRING1:ASCII   "this is an example string",0
ENDMARK:
LENGTH: H       ENDMARK-STRING
STRING2:ASCII	"this is another example string",0
POINT1: W       STRING1
POINT2: W       STRING2

Rewrite the above code with ALIGN directives insterted where they should be to assure that all halfwords and words are properly aligned. (1 point, 0.2 point penalty for each missing or extra align)

STRING1:ASCII   "this is an example string",0
ENDMARK:
        ALIGN   2
LENGTH: H       ENDMARK-STRING
STRING2:ASCII	"this is another example string",0
        ALIGN   4
POINT1: W       STRING1
POINT2: W       STRING2

113201D1
C213F2F3
000662F4
000010E5

a) Disassemble these words into a sequence of hawk instructions, and give those instructions in SMAL Hawk notation. (1.0 points, 0.1 points penalty per error in opcode, register or field.)

Hint: All the instructions are found in Chapter 4, Appendix B of the Hawk Manual is the primary resource for this kind of problem, in general, the Hawk emulator can solve this problem for you, but you will be expected to be able to disassemble code by hand using Appendix B on exams.

        LIS     R1,1
        ADD     R2,R1,R1
        MOVE    R3,R2
        ADDSI   R3,2
        ADDI    R4,R2,6 ; alternately, LEACC   R4,R2,6
        LIL     R5,#10

b) What registers does the above code change, and what values does it leave in those registers, when it is done. (0.5 points, 0.1 point penalty per error)

Hint: Again, you will be expected to be able to solve this with pencil, paper and the Hawk manual, but you can check your work using the Hawk emulator.

        LOADA   rd,address

Here, rd is the destination register, address is a 32-bit literal memory address, and the instruction loads the word from that memory address into the destination register.

A problem: Write a SMAL Hawk macro that implements this. (0.5 points, 0.1 per missing or confused element)

        MACRO   LOADA rd,address
          LIW   rd,address
          LOADS rd,rd
        ENDMAC