VHDL Mock Test 2

1. For any concurrent assignment statement, which of the following is true?

2. Which of the following logical operator has the highest precedence?

3. Which of the following is equivalent division by 2 operator?

4. One can perform basic operations between different data types.

5. What is the type of result for comparison operators?

6. Transport delay is a kind of __________

7. Which of the following can’t be the value of x? Refer to the VHDL code given below.

TYPE color IS (red, green, blue, black, white, gray);
SUBTYPE primary IS color RANGE red to blue;
VARIABLE x: primary;

8. What will be the value of y after the execution of the following VHDL code?

Library ieee;
USE ieee.std_logic_1164.all;
USE ieee.std_logic_arith.all;
…
SIGNAL m : UNSIGNED (3 DOWNTO 0);
SIGNAL n : UNSIGNED (3 DOWNTO 0);
SIGNAL y : STD_LOGIC_VECTOR (7 DOWNTO 0);
y <=CONV_STD_LOGIC_VECTOR ((m+n), 8);
…

9. Refer to the VHDL code given below, which of the following signal is driven by multiple drivers?

LIBRARY IEEE;
USE IEEE.std_logic_1164.all;
ENTITY function IS
PORT (b, c : IN BIT;
a, d : OUT BIT);
END function;
ARCHITECTURE behavior OF my_func IS
BEGIN
a <= b;
a <= c;
d <= b;
END behavior;

10. What is the type of result of MOD operator?