ECE474                          Quiz 3                               5.15.2017

1.[5] In simple terms, what is the difference between wire and reg data types?

  reg is a variable and as such as memory or state.  wire has neither.


2.[35] For a-g below, assume that the variable z has been defined as a 12 bit
       reg type. In other words, z has been declared as: 

       reg [11:0] z;

    For assignment statement below, state the value of z. You must use underscores 
    to make your answer more readable. 

    a.) z = 8’b1011;   z = 0000_0000_1011

    b.) z = 3’b1111;   z = 0000_0000_0111

    c.) z = 4’shB;     z = 1111_1111_1011

    d.) z = 5’shC;     z = 0000_0000_1100

    e.) z = 8’shF2;    z = 1111_1111_0010

    f.) z = ’sh5A;     z = 0000_0101_1010

    g.) z = -’shA1;    z = 1111_0101_1111



3.[20] For the assignments below,  Is the result true of false?

    a.) y = 8'b0110_1110 && 4'b0;          False

    b.) y = 8'b0110_0010 || 4'b0;          True

    c.) y = 8'b0110_1110 && 8'b1001_0001;  True

    d.) y = !(8'b1001_0001);               False

    e.) y = 8'b0110_1110 && 8'b10x1_0xx1;  True 



4.[25] Suppose a = 4'b0100, b = 2'01, and c is declared to be reg [11:0] c.
       What is the value of c: after the assignment? 

    a.) c = a & b       c = 0000_0000_0000

    b.) c = a ^ b       c = 0000_0000_0101

    c.) c = ~b          c = 1111_1111_1110

    d.) c = ^a          c = 0000_0000_0001

    e.) c = {b,a,2{a}}  c = 0100_0100_0100