13.1 Assignment 1
Due: 9.00AM on Monday 14th April 2008 (beginning of Week 6)
Overview
This assignment will contribute 10% of your overall assessment for the course. Recall
that you must pass all three hurdles (WebLearn tests, assignments and exam) in order
to complete the course.
• This assignment specification is subject to change. Ensure that you keep up to date
with the Official Announcements forum of the course’s Blackboard.
• Refer to page 196 onwards for submission requirements applicable to this assignment,
i.e. what to submit and how.
• Refer to page 200 for details on late submissions and extensions.
Section 1: Data representation 25 marks
Answer the following questions. To receive full marks you must show all working.
Answers with inadequate working will receive zero marks.
Question 1 3 × 1 = 3 marks



Convert the binary number 0101 1010 1101 into octal, hexadecimal and decimal.

Octal: 2655
010 = 2 | 110 = 6  | 101 = 5 | 101 = 5

Hexadecimal: 5AD
0101 | 1010 | 1101 

Decimal: 1453
0101 1010 1101
1 + 4 + 8 + 32 + 128 + 256 + 1024





Question 2 3 × 3 = 9 marks
Perform the following binary arithmetic, showing all carry/borrow bits and stating
8-bit validity for both unsigned and 2’s complement interpretations



1011 0011 +  1110 1100
2's complement;
       1111		(carry)
	1011 0011
      +1110 1100
       11001 1111 (VALID)

8bit;
       1111		(carry)
	1011 0011
      +1110 1100
       11001 1111 (INVALID)          
  
1001 0110 −  0010 0011
2's complement;

      10  11 1            (carry)
	1001 0110
       -0010 0011
        1101 1100 
+1    1101 1101
        0111 0011        (INVALID)                              

8bit;
          1       11   (borrow) 
	10010110
       -00100011
        01110011  (VALID)







0011 1011 −  1001 1010
2's complement;
       01111 111      (Carry)
	0011 1011
	1001 1010
	0110 0101
+1 	0110 0111
        1010  0010 (INVALID)

8bit; 
        1              (borrow) 
	0011 1011
       -1001 1010
        0010 0001 (INVALID)  


13.1. ASSIGNMENT 1 203
Question 3 2 × 2 = 4 marks
Perform the following arithmetic in hexadecimal assuming unsigned data, again showing
all carry/borrow bits and stating whether the solution is valid:

a) $ ABCD + $ 2FEE


        1 11            (Carry)
 	$ABCD 
+	$2FEE
	$DBBB (VALID)

b) $ D3FD − $ ABBA
	   1		(Borrow)
	$D3FD
-	$ABBA
	$2843		(Valid) 



Question 4 4 marks
Convert the decimal value 0.39375 into an 8-bit binary fraction.
Question 5 5 marks


Perform the following multiplication twice (once interpreting the data as unsigned, and
once interpreting the data as signed):
% 1001 1110 × % 110
Unsigned; 
         1001 1110
	x	  110
         0000 0000
         1111 1100
         1111 1000      
                  0100
			 (carry)
Section 2: Assembly language programming 5 marks

NOTE TO MARKER:
I completely rewrote the code for this part, I didn't believe we had to use the sample code and then modify it until I reread over the assignment just before submitting to find that we were meant to do that. I believe though that my code still does the requirements so I shall submit it in the hope to get some marks still! Screen shots provided below.
Thanks 

Code; 
 org $1000
 move.l #$7ffe,sp	;init stack pointer
 move.w $2000,d1 	;get data 1
 move.w $2002,d2	;get data 2
 move.w $2004,d3 	;get data 3
 move.w $2006,d4	;get data 4
 add.w  $2000,d2	;add d1 result 1
 move.w d2,result1	;Save Result 
 move.w result1,$2008	;Save Result
 add.w  $2004,d4	;add d3 to d4
 move.w d4,result2		;
 move.w result2,$2010   	;Save Result
 move.b #228,d7		;return to simulator
 trap #14		;	
 org $2500		
result1 dc.w 1 		;
result2 dc.w 2		;
 end			;no more to assemble


Screen shot;