22C:060 Computer Organization
Sample solution to Assignment 1
(Chapter 1, Exercise 10) Dealing with self-modifying codes is challenging. Debugging
can be a nightmare. Codes can be accidentally corrupted too. Security holes are a matter
of concern and may be easy to plant. On the other hand, self-modifying codes can
provide new opportunities to write innovative codes. (In the early days, they were used to
simulate indexed addressing)
(Chapter 2, Exercise 2(c)) 652 10 = 1621 7
(Chapter 2, Exercise 4(b)) 57.55 10 = 111001.100011 2
(Chapter 2, Exercise 6(c))
Binary
Decimal
Binary
Decimal
000
001
010
011
+0
+1
+2
+3
100
101
110
111
-4
-3
-2
-1
(* Some of you did not understand the meaning of 3-bit word.)
(Chapter 2, Exercise 34(b))
Original integer 10011001110
After applying Hamming code 1 0 0 1 1 0 1 0 1 1 1 0 0 0
There are four parity bits in positions 1, 2, 4, 8. Their values are chosen so that the even
parity is maintained for the following bit combinations:
(8,9,10,11,12,13,14) (4,5,6,7,12,13,14) (2,3,6,7,10,11,14) (1,3,5,7,9,11,13)
Problem 6-7
(a) –11.625 IEEE 754 format 1 10000010 011101 ….0 (23bits)
(b) + 0.15625 IEEE 754 format 0 01111100 010000 … 0 (23 bits)