0 votes
in VHDL by (200 points)

What are VHDL attributes and how do I use them?

2 Answers

0 votes
by (300 points)

Attributes are a useful VHDL mechanism that allow you to extract additional information of an object. To use an attribute we write the name of the object we want to apply the attribute on followed by an apostrophe and the attribute name. Attributes are widely used when writing generic VHDL code.

Example :

constant width_of_some_input : integer := some_input ' length ; -- "some_input" maybe an entity port of unconstrained length. By using the ' length attribute we are able to extract its length.

0 votes
by (260 points)

Attributes are a way of attaching additional information to an entity in VHDL. Attributes are assigned to entities through attribute specifications.

When an attribute specification is done, the declared attribute name is used for reference. While declaring an attribute, a type identifier is mentioned to define the type of user-defined attribute. A simple syntax is given below for attribute declaration:

attribute att_name : type;

For assigning an attribute to the desired entity, attribute specification is done as depicted by the simplified syntax below:

attribute att_name of item : item_class is expression;

In the above code snippet, 'expression' specifies the attribute value.

Hardware Coder Community

© 2022 by Hardware Coder. User contributions are licensed under cc by-sa 4.0 with attribution required. Attribution means a link to the question, answer, user, etc on this site.

This site is owned and operated by Hardware Coder in McKinney, Texas.

Send Us A Message
About Us

By using this site, you agree to the following:

Privacy Policy
Terms and Conditions
DMCA Policy
Earnings Disclaimer
Legal Disclaimer

...