From NonLinear Circuits website:
This module is a slope/envelope/function generator. The core is based on that seen in the Serge Slope Generator, Korg PS3100 EG, Maths, Rampage and a dozen other Eurorack modules. The rest of it has been trimmed down or gutted to the minimum number of parts to make it work.
If nothing is patched into GATE, the module is free running, ranging from a few minutes per cycle to audio rates. GATE can also be used as a SLEW input if you want to make a stepped sequence a bit rubbery.
Patching into the ↑CV or ↓CV jacks causes the associated pots to become attenuators for the signals you have patched in.