I've highlighted this symbol from page 30 of the TMC2100 datasheet:
Based on the context, which says "only rising edges are active", I'm guessing it means that a signal is detected when the input voltage rises from 0.44×VCC_IO to 0.56×VCC_IO within a given period of time (e.g. from 2.2V to 2.8V if VCC_IO is 5V).
Is that correct, or does it have a different meaning?
Does anyone have a link to a cheat sheet that contains this symbol?