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14.6.2. While Loop

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The while loop is a condition-controlled loop that executes as long as the specified condition is true. It is a PRE-TEST loop (condition checked before execution) and is NOT synthesizable.

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Syntax and Structure

Verilog

Characteristics

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  • Condition is checked BEFORE each iteration

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  • If condition is false initially, loop never executes

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  • Iteration count unknown until runtime

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  • NOT synthesizable (testbench only)

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  • Must have timing control to avoid infinite zero-time loop

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Basic Examples

Verilog

While Loop vs For Loop Equivalence

Verilog

Common While Loop Patterns

Verilog

Critical: Avoiding Infinite Loops
 

âš  DANGER: While loops without timing controls will create INFINITE ZERO-TIME LOOPS that hang the simulator!

Verilog

For loop

Repeat loop
 

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