Why testbenches are needed in VHDL - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a testbench entity in VHDL.

VHDL

entity [1] is
end entity;

Drag options to blanks, or click blank then click option'

Atestbench

Barchitecture

Ccomponent

Dprocess

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'architecture' or 'component' instead of the entity name.

The testbench entity is declared with the name testbench to start the testbench code.

2fill in blank

medium

Complete the code to instantiate the design under test (DUT) inside the testbench.

VHDL

uut: entity work.[1] port map();

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Adesign

Btestbench

Cdut

Darchitecture

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'testbench' or 'architecture' as the design name.

The design under test is usually instantiated with the entity name dut inside the testbench.

3fill in blank

hard

Fix the error in the process statement that drives the clock signal in the testbench.

VHDL

process
begin
  clk <= not clk;
  wait for [1] ns;
end process;

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A100

B10

C1

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using 0 ns causes no delay and simulation issues.

The clock period delay is commonly set to 10 ns for a 50 MHz clock in testbenches.

4fill in blank

hard

Fill both blanks to create a dictionary comprehension that filters signals by length in Python (conceptual analogy).

VHDL

signals = {sig[1] str(len(sig)): len(sig) for sig in signal_list if len(sig) [2] 3}

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A**

B>

C<

D+

Attempts:

3 left

💡 Hint

Common Mistakes

Using '**' for concatenation or '<' for filtering incorrectly.

The dictionary comprehension adds the length to the signal name and filters signals with length greater than 3.

5fill in blank

hard

Fill all three blanks to create a dictionary comprehension that maps signal names to their lengths if length is greater than zero.

VHDL

signal_lengths = [1]: [2] for [3] in signals if len([3]) > 0}

Drag options to blanks, or click blank then click option'

Asig

Blen(sig)

Dsignal

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing variable names or using incorrect keys or values.

The comprehension maps each signal name to its length, iterating over signals named 'sig'.