AN015: Creating Schmitt-Triggered Inputs on the P8X32A Propeller Microcontroller

Abstract: Schmitt-triggering diminishes or eliminates logic-level uncertainty from signals having slow rise/fall times and those burdened  with superimposed noise. It achieves this using positive feedback to  create a hysteresis band about the threshold of a logic input, which  must be crossed in its entirety to effect a state change. With the addition of external resistors, along with programmed positive feedback, the P8X32A can enjoy the benefits of Schmitt-triggering on any of its inputs.