Catalog / VHDL Cheatsheet
VHDL Cheatsheet
A quick reference guide to VHDL (VHSIC Hardware Description Language), covering syntax, data types, operators, and common constructs used in digital circuit design.
Basic Syntax and Structure
Entity Declaration
The
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Example:
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Architecture Body
The
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Example:
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Libraries and Packages
VHDL uses libraries and packages for predefined types and functions.
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Data Types and Operators
Standard Data Types
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Represents a single bit with nine possible values (‘U’, ‘X’, ‘0’, ‘1’, ‘Z’, ‘W’, ‘L’, ‘H’, ‘-’). |
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An array of |
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Represents signed integer values. Range is implementation-dependent. |
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Represents boolean values ( |
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Represents floating-point values. |
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Represents time values with a specified unit (e.g., |
Operators
Logical Operators |
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Relational Operators |
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Arithmetic Operators |
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Shift Operators |
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Concatenation Operator |
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Concurrent and Sequential Statements
Concurrent Statements
Concurrent statements execute in parallel.
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Sequential Statements
Sequential statements execute in order within a process.
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Advanced Concepts
Components
Components are instances of entities used within an architecture.
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Functions and Procedures
Function |
A function returns a value and cannot have side effects.
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Procedure |
A procedure does not return a value directly and can have side effects.
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Generics
Generics provide a way to parameterize entities and components.
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Example:
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