VHDL Mock Test 5 - Sanfoundry

10%

Question 1 of 10

1. Which of the following is the default type of ports of an entity?

Signals

Variables

Functions

Constants

Question 1 of 10

Question 2 of 10

2. Which of the following can’t be used in a process when it has any WAIT statement?

LOOP

CASE

Sensitivity list

Question 2 of 10

Question 3 of 10

3. Loop is a ________ statement.

Assignment

Concurrent

Functional

Sequential

Question 3 of 10

Question 4 of 10

4. Which logic circuit is described in the following code?

LIBRARY IEEE;
USE IEEE.std_logic_1164.all;

ENTITY system IS
GENERIC (l : INTEGER := 3);
PORT ( a, b : IN STD_LOGIC_VECTOR ( l DOWNTO 0);
              c     : IN STD_LOGIC;
              x     : OUT STD_LOGIC_VECTOR (l DOWNTO 0)
              y     : OUT STD_LOGIC);
END system;
ARCHITECTURE design OF system IS
BEGIN
PROCESS (a, b, c)
VARIABLE z : STD_LOGIC_VECTOR ( l DOWNTO 0);
BEGIN
z(0) := c;
FOR I IN 0 TO l LOOP
x(i) < = a(i) XOR b(i) XOR z(i);
z(i+1) <= (a(i) AND b(i)) OR (a(i) AND z(i)) OR (b(i) AND z(i));
END LOOP;
y <= z(l);
END PROCESS;
END design;

4-bit half adder

4-bit full adder

4-bit half subtractor

4-bit full subtractor

Question 4 of 10

Question 5 of 10

5. Use of constants is to _________

Represent default value

Represent local information

Pass value between entities

Represent wires

Question 5 of 10

Question 6 of 10

6. In combinational logic, how many WAIT statements can be used?

Question 6 of 10

Question 7 of 10

7. Where should one use WARNING severity level?

To give a warning about wrong conditions

To stop the execution

To pass the message from simulation

To alert the user about unexpected conditions

Question 7 of 10

Question 8 of 10

8. A FOR loop is inside a WHILE loop. Inside the FOR loop, the EXIT statement is used in such a way that after 4 iterations, it will execute. After the execution of EXIT statement, the control will be passed ________

At the next iteration of WHILE loop

At the next iteration of FOR loop

Outside the WHILE loop

Outside the FOR loop

Question 8 of 10

Question 9 of 10

9. What does the next statement in loops do?

Exits the loop

Starts the next loop by ending the current

Skips the current iteration

Skips the next line of the loop

Question 9 of 10

Question 10 of 10

10. What is the use of WHILE loop?

To repeat the statement finite number of times

To repeat statements inside until any condition is false

To repeat the statements for infinite time

To repeat the statement until any condition holds true

Question 10 of 10