@cfelton @josyb Thank you for your comments, they are helpful for getting started.
For my previously interested idea, I've just read the FIRRTL specification roughly and gained some basic knowledge. I've been working on the MyHDL Manual to get more familiar with MyHDL, but there is still no inspiration now.
@cfelton Since I know the Fixed-point Compiler idea is among the project ideas, do you have any further suggestion if I give a try on this idea now? Maybe I should write some prototype and create a pull-request immediately?
Looking forward to your reply.