Custom verilog emission

Type of issue: other enhancement

What is the use case for changing the behavior?

@azidar mentioned that you were looking at adding a special node type to firrtl, @albertchen-sifive.

I’m interested in being able to support a use-case where a chisel annotation is used to emit custom verilog. For example, I’d like to be able to emit #ifdef guards for simulation around Analog types so we can use Verilog real.

Is this something close to what you’re working on? If so, I’d like to be involved.

Impact: unknown

Development Phase: proposal

[seldridge]

I think there are two things here. You’d like to be able to add transforms that run only for a specific emitter. You’d also like to be able to override how specific nodes are emitted and to add custom nodes where you define their emission behavior.

[albertchen-sifive]

yep, I would like to add some custom node type that can be extended to emit things like #ifdef and such. I haven’t gotten around to implementing anything yet though. @azidar you mentioned that there was some cleanup on some of the firrtl passes that should be done before starting?