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Modules & Nets
module input output wire reg logic parameter localparam module instantiation named port mapping generate
Combinational Logic
assign always @* always_comb blocking assignment ternary operator case casez casex caveat concatenation replication
Sequential Logic
always posedge nonblocking assignment always_ff synchronous reset asynchronous reset clock enable counter shift register edge detector register pipeline
Data & Operators
bit vector signed value part select indexed part select arithmetic operators logical operators bitwise operators reduction operators shift operators comparison operators
Procedural Control
if else for loop while loop repeat forever break continue function task automatic lifetime
Finite State Machines
state parameter enum state state register next-state combinational Moore FSM Mealy FSM default state recovery one-hot state output register transition condition
Testbenches
initial block delay control clock generation $display $monitor $finish test vector loop task stimulus $readmemh assert property
Advanced RTL
interface modport struct packed union packed typedef package import generate if generate for parameterized module signed arithmetic
Verilog / Finite State Machines

default state recovery

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

10 min read • Intermediate

default state recovery is an atomic Verilog topic inside Finite State Machines. This lesson focuses on how the default state recovery construct is written, what it changes, and when it is the right tool.

Trace the example line by line. Identify the exact syntax for default state recovery, 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-06-07-default-state-recovery.sv
verilog Try It Live 
always_comb begin next_state=IDLE; case(state) IDLE:...; RUN:...; default:next_state=IDLE; endcase end
Edge case / engineering note

For default state recovery, 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

default state recovery Mastery Check →
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