This week, I implemented and verified a software model of the envelope detector module, which makes plots of like the image below for given values for attack, decay, sustain, and release.

I’ve implemented it with hardware in mind, so it should be very easy to port it over to SystemVerilog. I’ve also worked on the software model for the wave table oscillator, which is proving to be more difficult than expected. I’ve put a lot of thought and testing into high level decisions like standardization of fixed point numbers, how much resolution to store for our wavetables, and how to play a read-only wave at an arbitrary frequency.

I’m still slightly behind schedule, but it’s definitely recoverable. Next week I hope to finish the oscillator model, which should mostly give the LFO model for free. Then, the first round of software simulators will be complete and I can start moving to SystemVerilog.