Verilog状态机编译报错：endmodule附近存在语法错误求助

Hey Mike, sorry to hear you're stuck with that vague endmodule error—those can be such a frustrating headache when the compiler doesn't give you specifics! Let's walk through the most common culprits that cause this kind of issue, even when you think your structure looks right:

• Mismatched or missing parentheses/braces
  This is the #1 culprit! Check every ( against its ), every begin against its end, and every case/casex/casez against its endcase. Even one missing or extra brace deep in your state logic (like inside a combinational block for next-state logic) can throw the compiler off, making it think the module never properly closes.

• Unterminated comments
  If you started a multi-line comment with /* but forgot to end it with */, the compiler will treat everything after that as a comment—including your endmodule line. Double-check all your comment blocks, especially if you recently added or edited them.

• Syntax errors in port declarations
  Your module starts with module FSM(in...—make sure your port list is properly formatted. Missing commas, extra colons, or incorrect data types (like forgetting wire/reg in ANSI-style ports) can mess up the compiler's parsing, leading it to misinterpret where the module body ends.

• Missing semicolons
  A forgotten semicolon at the end of a register declaration, assign statement, or parameter definition can throw off the entire parsing sequence. Scan through your code line by line (or use your editor's syntax highlighting) to spot any lines that should end with ; but don't.

• Incorrectly nested constructs
  State machines often have nested begin/end blocks inside case statements. Make sure you didn't accidentally close a block too early (or too late) — for example, ending a begin before your state transitions are fully defined can leave the compiler looking for an extra end that doesn't exist, which gets blamed on the endmodule line.

If you can share a snippet of your full code (even just the parts around your state logic and port declarations), we can narrow this down even further. But these steps should cover most of the common issues that cause that vague endmodule error.

内容的提问来源于stack exchange，提问作者Mike