如何在DC综合时保留代码中的net？

1. assign a = in1 & in2;
   
2. assign b = in1 | in3;
   
3. assign c = a & b;

在dc里，help -"*net" 搜索关于Net的命令，我记得有这种命令的

调用一个库里的buffer，把b经过buffer输出，DC里设置dont touch

When you set the enable_keep_signal variable to true, the tool preserves nets and issues a warning about the preserved nets during compilation. The tool sets an implicit size_only attribute on the logic connected to the nets to be preserved. To mark a net to be preserved, label the net with the keep_signal_name directive in the RTL and set the hdlin_keep_signal_name variable to user or user_driving. Preserving nets might cause QoR degradation.
要DC里设变量，完了还要在RTL里加注释。详见preug。

同意楼上的做法， 你需要保留的net 用standcell 的方式来连接， dc 的时候设置don't touch 就可以了