Hi,
Some doubts about GPIO input qualification,
1) In the picture below, what's the sample point? If the GPIO signal's frequency is higher than sample window, what happens?
2) The sampling window is 6 samples, but actually, after 5 samples' time, the output could changed, is that right?
3) Beside these, is there any other possibility, which influences the time t?
Br, Jordan
Hi Jordan,
Thanks for your questions. Please download the latest TRM as it clarifies some of these questions:
1) In the picture below, what's the sample point?
See latest diagram, it is the falling edge:
If the GPIO signal's frequency is higher than sample window, what happens?
As the section mentions, it will ignore the signal if it doesn't stay stable during the entire sampling window:
2) The sampling window is 6 samples, but actually, after 5 samples' time, the output could changed, is that right?
Yes, but if it changes at all during the next 5 samples, it will ignore it as "noise". It must be stable for a full X-1 samples, where X is the sampling window.
3) Beside these, is there any other possibility, which influences the time t?
Other than your settings for qualification, no, there are no other influences to it.
Regards,
Vince
