Function application

good question.

component is meant to be direct definition of a design modul with its inputs/outputs and internal functionality.

function( also has inputs/outputs and internal functionality but these are not meant to be direct module definition but rather a piece of user code to be inserted when that function is called up.

it could due to the way HDL evolved (component from symbol era, function of programming language)

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Hi

When we use “ function” and where is its exact usage? what is the difference between it and “component”? if it is possible explain it by examples.

Thank you

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A component is basically an entity. And of course an entity is something which encapsulates your logic design. It has inputs, outputs, internal signals and whatever logic you can imagine.

A function is a bit of logic which executes in delta time, and is commonly used to implement code which gets reused. The various conversions you find in numeric_std, such as to_unsigned(), are examples of functions. Unlike its cousin the procedure, a function may not include any delay or wait mechanisms.