保存
システムタスク $save(“filename”) でシミュレーションの状態をファイルに保存。
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| initial begin | |
| #100; $display("a"); | |
| #100; $display("b"); | |
| $save("checkpoint"); | |
| #100; $display("c"); | |
| #100; $display("d"); | |
| end |
差分保存の $incsave(“incremental_filename”) もある。
再開
$restart(“filename”) で再開。書くならこんな感じ？
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| initial begin | |
| integer fd; | |
| fd = $fopen("checkpoint", "rb"); | |
| if (fd !== 0) begin | |
| $fclose(fd); | |
| $restart("checkpoint"); | |
| end | |
| end |
VCS の場合、simv -r checkpoint で指定可能なよう。
注意点
（ツールの実装によるかもしれないけど）$save を呼び出した同時刻までの処理が完了した状態で保存されるので、次のような場合 CHECKPOINT は再開時に表示されない。
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| initial begin | |
| $save("checkpoint"); | |
| $display("CHECKPOINT"); // $save 呼び出しと sim 時間が同じ | |
| end |