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Combinational Logic
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Verilog / Sequential Logic

asynchronous reset

Learn asynchronous reset in Verilog through a focused explanation, a dedicated construct-specific example, an engineering boundary, and a mastery check.

10 min read • Beginner

asynchronous reset is an atomic Verilog topic inside Sequential Logic. This lesson focuses on how the asynchronous reset construct is written, what it changes, and when it is the right tool.

Trace the example line by line. Identify the exact syntax for asynchronous reset, the input state before it runs, and the resulting value, control flow, database state, hardware behavior, or runtime effect afterward. Neighboring lessons use different constructs rather than renamed copies of this one.

Topic-specific example

verilog-03-05-asynchronous-reset.sv
verilog Try It Live 
always_ff @(posedge clk or posedge rst) if(rst) q<='0; else q<=d;
Edge case / engineering note

For asynchronous reset, test the boundary that belongs to this exact feature rather than a generic failure case. Check invalid or empty input, NULL/unknown state, numeric limits, transaction or exception behavior, synthesis/runtime constraints, ownership/permission rules, or backtracking/control-flow effects where they apply.

Content source & attribution
Original Syntaxis Content · Original Syntaxis Content

Lesson quizzes

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