Report statement for debug output in VHDL - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the report statement in VHDL?

The report statement is used to display messages during simulation, helping to debug and understand the behavior of the VHDL design.

beginner

How do you write a simple report statement in VHDL to show the message 'Signal value changed'?

Use: <br>report "Signal value changed";<br>This prints the message during simulation.

intermediate

What are the severity levels available in a VHDL report statement?

Severity levels include: <br>- NOTE (default)<br>- WARNING<br>- ERROR<br>- FAILURE<br>They indicate the importance of the message.

intermediate

How do you add a severity level to a report statement in VHDL?

Syntax: <br>report "Message" severity WARNING;<br>This sets the message severity to WARNING.

intermediate

What happens if a report statement with severity ERROR or FAILURE is executed during simulation?

The simulator usually stops or flags an error, helping to catch serious problems early in the design.

Which VHDL statement is used to print debug messages during simulation?

A report

B print

C display

D echo

The report statement is the correct way to output messages in VHDL simulations.

What is the default severity level if none is specified in a report statement?

A WARNING

B ERROR

C NOTE

D FAILURE

If no severity is given, the default is NOTE.

How do you write a report statement with a WARNING severity?

A report WARNING "Warning message";

B report "Warning message" severity WARNING;

C report "Warning message" level WARNING;

D report "Warning message" with WARNING;

The correct syntax is report "message" severity WARNING;.

What effect does a report statement with severity FAILURE have during simulation?

A Ignores the message

B Prints a note only

C Logs the message silently

D Stops the simulation or flags a critical error

Severity FAILURE usually stops the simulation or signals a critical error.

Which of these is NOT a valid severity level in VHDL report statements?

A CRITICAL

B WARNING

C ERROR

D NOTE

CRITICAL is not a valid severity level in VHDL; valid levels are NOTE, WARNING, ERROR, and FAILURE.

Explain how to use the report statement in VHDL to help debug your design.

Think about how you would tell the simulator to show messages and how important those messages are.

Describe the difference between the severity levels WARNING and ERROR in a VHDL report statement.

Consider how serious each message is and what the simulator does when it sees them.