Tested with RP2350 (at 125MHz to be comparable), WAIT GPIO and WAIT PIN are both the same, long as WAIT PIN on RP2040.
But the synchronizers are inserting only one additional clock delay (instead of 2).
Schmitt trigger has minimal delay (around 0.1 ns), it stabilizes the signal at very very slow slope (otherwise tends to oscillate).
So the general response time is 2*clk + internal delay (RTT around 5ns in my case), add one more clk for synchronizers.
NO SYNC clk=8ns, first marker(X3) 2*8+5 = 21ns
SYNC clk=8ns, second marker(X2) 3*8+5 = 29ns
But the synchronizers are inserting only one additional clock delay (instead of 2).
Schmitt trigger has minimal delay (around 0.1 ns), it stabilizes the signal at very very slow slope (otherwise tends to oscillate).
So the general response time is 2*clk + internal delay (RTT around 5ns in my case), add one more clk for synchronizers.
NO SYNC clk=8ns, first marker(X3) 2*8+5 = 21ns
SYNC clk=8ns, second marker(X2) 3*8+5 = 29ns
Statistics: Posted by gmx — Sat Jun 14, 2025 12:37 am