am335x Capture: Has the am335x input pin the schmitt trigger?

Electrical noise in the system is much more likely to effect timing relationships of slow changing digital signals that fast changing digital signals.

One example of system noise is small voltage differences between the internal VSS and the external VSS signals produced by the inductance and resistance of PCB and package signal traces.  The digital input buffers will see the voltage difference between internal and external VSS signals as input noise since external signals sourcing the the digital input buffers are referenced to the external ground while the input buffers are referenced to internal VSS.  This VSS noise is much more likely to effect slow changing signals applied to digital input buffers.  Therefore, most high speed timing critical interfaces have a maximum input rise/fall time of 5ns.  The capture input does not have any specific timing relationship to any other signals, but this VSS noise may limit the repeatability of multiple capture events on the same input.

Hysteresis for inputs can be found in Table 3-11 DC Electrical Characteristics of AM335x Data Sheet.

Hysteresis will help eliminate possible input glitches when sourced with slow changing signals, but may not resolve slight timing shifts introduced when noise is added to the slow changing signal.

Regards,
Paul