Verilator v5試す(timingとbinaryオプション)

Verilator

2022/10/29に Verilator v5.002がリリースされたようです。

Revision Historyによると

・Require C++20 for the new –timing features. Upgrading to a C++20 or newer compiler is strongly recommended.
・Support the Active and NBA scheduling regions as defined by the SystemVerilog standard (IEEE 1800-2017 chapter 4). This means all generated clocks are now simulated correctly (#3278, #3384). [Geza Lore, Shunyao CAD]
・Support timing controls (delays, event controls in any location, wait statements) and forks. [Krzysztof Bieganski, Antmicro Ltd] This may require adding –timing or –no-timing. See docs for details.
・Introduce a new combinational logic optimizer (DFG), that can yield significant performance improvements on some designs. [Geza Lore, Shunyao CAD]
・Add –binary option as alias of –main –exe –build –timing (#3625). For designs where C++ was only used to make a simple no-I/O testbench, we recommend abandoning that C++, and instead letting Verilator build it with –binary (or –main).

ということで、Timing Controlがサポートされたということで早速試してみました。

Mac(Monterey 12.6)だと brew installでインストールされると思います。
私は元々入れていたので、brew update/upgradeを実行しました。

$ verilator --version
Verilator 5.002 2022-10-29 rev UNKNOWN.REV

実行コード＆オプション自体はこちらを参考にしました。

module our;
  initial begin
    $display("Current time = %t", $realtime);
    $display("Hello World");
    #10;
    $display("Current time = %t", $realtime);
    $finish;
  end
endmodule

$ verilator --binary -j 0 -Wall our.v
$ ./obj_dir/Vour
Current time =                    0
Hello World
Current time =                   10
- our.v:7: Verilog $finish

おぉ！きちんと #10;が効いてますね。

ちなみに、--no-timingを付けるとエラーメッセージが出てきます。

$ verilator --no-timing --binary -j 0 -Wall our.v

%Warning-STMTDLY: our.v:5:5: Ignoring delay on this statement due to --no-timing
                           : ... In instance our
    5 |     #10;
      |     ^
                  ... For warning description see https://verilator.org/warn/STMTDLY?v=5.002
                  ... Use "/* verilator lint_off STMTDLY */" and lint_on around source to disable this message.
%Error: Exiting due to 1 warning(s)