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Published 20 hours ago • verified publisher icon SpinalHDL

Unused registers

Open dnltz opened this issue 5 years ago • 1 comments

I just want to report some unused flip-flop registers. They got removed during elaboration and since they are never used, they could also be removed? We should discuss how to handle these.

I found these for my current configuration:

  • CsrPlugin_lastStageWasWfi
  • DebugPlugin_firstCycle
  • DebugPlugin_secondCycle

If I know how to handle these I could report more by trying out some other configurations.

dnltz avatar Jun 16 '19 15:06 dnltz

In general, i'm not shy to have flip flop in the netlist which only have a purpose for simulation / debug purposes and which will be removed at synthesis. For instance : https://github.com/SpinalHDL/VexRiscv/blob/master/src/main/scala/vexriscv/VexRiscv.scala#L101

But the three regs that you point are dead code that i should remove, nice catch ^^

Dolu1990 avatar Jun 25 '19 07:06 Dolu1990