Maybe you need the other nodes (ramp and latch) hooked to something. Here's the source code for the tap tempo block FYI.
SpinCAD Designer is an open source Java project which allows creation of patches for the Spin FV-1 audio DSP chip. - HolyCityAudio/SpinCAD-Designer
github.com
I don't really feel like sorting through all that right now to figure out how to use the block. But, it says the author is "slacker". So, I'm guessing the block is supposed to do his tap tempo delay code from his Babelfish project.
Spinsemi FV-1 based pedal ideas. Contribute to slackDSP/Babelfish development by creating an account on GitHub.
github.com