CS250 Homework Midterm Practice

a) Solve this homework and turnin your handwritten or printed answers on during  the midterm exam. You will find similar questions in the midterm exam.
I will post the evening before the exam. I strongly suggest you to complete your homework on your own before looking at the solutions.

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1. Implement the boolean function for :xsegment b for a 7-segment decoder. Using four switches w, x, y, z  choose the digits 0, 1, 2, 3,4,5,6,7,8,9,A,B,C,D,E,F in the seven segment display. 

a) Write the truth table for the segment b

w
 x
 y
 z
 b









































b) Write the Karnaugh maps for b














c) Using the Karnaugh maps, write the boolean expressions for segment a and b using a minimum "sum of products" boolean expression.

    b =




d) Draw the schematic of your implementation using NAND gates.



2. Draw a Flip Flop


a) Using NAND gates





b) Using NOR gates



3.  In each line write the name of the memory section where the variables are stored:

CS250 Spring2008 Midterm

int a = 5;  // a is stored in _____________

int b[20];  // b is stored in _____________

int main() {  // main is stored in _____________
{
    int x;    // x is stored in _____________

    int *p = (int *)malloc(sizeof(int)); // p points to memory stored in ___________
}


4. Enumerate the steps needed to load a program.








5. What is a "Dynamic Linker" and a "Static Linker".








6. Perform the following multiplication in binary. Also, show convert to decimal the operands and the result.


                                                  1001010 x 1101




               



7.  Perform the following division in binary, Also, convert to decimal the operands and the result.


                                               
                 1011 | 100101001











8.  Represent the number1.25 in binary using the IEEE 754 double representation. The formula is given:

Val in decimal = (-1)s x (1.m) x 2(e-bias) where:

bias = 1023
s = bit 63
e = bits 52 to 62
m= bits 0 to 51


Val in binary: ___________________________


CS250 Spring2008 Midterm 9.  Explain what is a "Pipe Stall" and how can be avoided.









10. Obtain the representation of number -58 using 8 bits. Verify that 78 + (-58) is equal to 20 using binary addition and complements of 2.









11. Write a function "int isBigEndian()" that will return 1 if the computer is big endian or 0 if it is little endian.




12. What is the difference between Harvard Architecture and Von Newman Architecture




13. What do CISC and RISC stand for and enumerate the characteristics of each.



14. Write the following characteristics of the ATMEGA328:

Program Memory (KB):
RAM (KB):
Clock Speed (Hz):
Number of I/O ports:
Number of A/D ports:

14. Rewrite the following program in AVR assembly language. Remember that int's in AVR are 2 bytes long.

int a = 6;
int b = 3;
int c;

void setup() {
  c = a + b;
}

loop()
{
}

15. Rewrite the following program in AVR assembly language. Remember that int's in AVR are 2 bytes long.

int a = 6;
int b = 4;
int c;

void setup() {
  c = a * b;
}

loop()
{
}

16. In x86-64 Assembly language implement the function int addarray(int n, int * array) that add all the elements of the array
passed as parameter. n is the length of the array.




17. In x86-64 Assembly language implement a program "maxmin" that prompts two integer numbers fom stdin and then displays the maximum, minimum and average of both: numbers. Here is an example of the usage:

bash> maxmin
a=5
b=8
max=8
min=5
avg=6