Put your social security number in the right hand corner of the page. Please do not put your name anywhere on this quiz. Failure to follow these instructions will cost you 1 point on the quiz. Note: Be sure to show all your work and no calculators. You will have until the end of class to complete the quiz. Description: `2C’ means two’s complement format.
1. (2 points) Add the following two 2C binary numbers:
Note:
Your answer should be in 2C binary (radix 2).
11111110
+
10000001
--------------
1- CO 011111112C
Is a 2C overflow produced? Justify your answer.
Yes, the numbers that are being added are negative (MSB – 1);
the answer is a positive
(MSB – 0) number.
2. (2 points)
a)
What port are the motors on for the HC11 board? Port B
What is the address for that port (0.5 extra credit)? $1004
b)
What port are the digital input sensors on for the HC11 board?
Port C
What is the address for that port (0.5 extra credit)? $1003
c) The following two lines of code are from the sample program given in class:
org RESET
fdb start
What do these two lines of code
do? They set
the start address for the reset
vector.
What is the value of the variable
constant `RESET’? $fffe
3. (3 points) Use the multiplication algorithm (with table) to convert 111101102 (this binary number is in 2C form) to radix base number 10 (decimal):
First: do
the two complement algorithm:
a) 11110110 -> 00001001
b) + 00000001 -> 000010102
Second: Table
Old Digit
New Radix
0 0
0 2
0 0 0 2
0 0 0 2
0 0 0 2
0 1 1 2
2 0
2 2
4 1
5 2
10 0 10
Third: Remember that MSB of 2C binary number was 1
so final answer is: -1010
4.
(3 points) Use the division
algorithm (with table) to convert –5310 to 2C binary form:
Note: You can go through hexadecimal or just directly to binary.
I. Going through hexadecimal
First: Division Table
Old Radix New Digit
53
16 3 5
3
16 0 3
Second: Two’s complement algorithm
3516 f – 3 f – 5
c a
+ 0 1
----------------------
c b
Third: convert to binary
c b
1100
1011 -> 110010112C
II. Going directly to binary
First: Division Table
Old Radix New Digit
53 2 26 1
26
2 13 0
13
2 6 1
6
2 3 0
3
2 1 1
1
2 0 1
Second: Two’s complement algorithm
a) 00110101 ->
11001010
b) + 00000001 -> 11001011 -> 110010112C