Hi > On Apr 26, 2017, at 12:29 AM, Jerry Hancock <jerry@hanler.com> wrote: > > Do typical frequency counters start their gate in phase with the incoming signal? I guess the > answer would be, "It depends." I was just thinking about how I would program the STM32F7 > counter I am designing. Since they don’t start (or stop) the gate in any specific relation to the input signal, the trick is to make sure you don’t get an extra count when the gate opens or closes. This is right back to the edge triggered vs level triggered issue. It also gets indirectly into the rechecking process in the MCU. Some of the “edge trigger” stuff is done in odd ways ….(= got two of the same after rechecking into a shift register …). Bob > > btw, Gilbert, a local time-nut, sold me a 5335 today so I will be able to buiild one great one > out of the two I will have. > > Jerry > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there.

I don’t know what I was thinking when I asked this question as we don’t control the gate timing in a referenced counter. > On Apr 26, 2017, at 3:59 AM, Bob kb8tq <kb8tq@n1k.org> wrote: > > Hi > >> On Apr 26, 2017, at 12:29 AM, Jerry Hancock <jerry@hanler.com> wrote: >> >> Do typical frequency counters start their gate in phase with the incoming signal? I guess the >> answer would be, "It depends." I was just thinking about how I would program the STM32F7 >> counter I am designing. > > Since they don’t start (or stop) the gate in any specific relation to the input signal, the trick is to > make sure you don’t get an extra count when the gate opens or closes. This is right back to the > edge triggered vs level triggered issue. It also gets indirectly into the rechecking process in the > MCU. Some of the “edge trigger” stuff is done in odd ways ….(= got two of the same after rechecking > into a shift register …). > > Bob > > >> >> btw, Gilbert, a local time-nut, sold me a 5335 today so I will be able to buiild one great one >> out of the two I will have. >> >> Jerry >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there.

High end frequency counters usually go to some effort to prevent synchronization between the input signal and the gate. Some DSOs do as well. Synchronization can exasperate certain errors and asynchronous operation provides better results when many measurements are averaged. On Tue, 25 Apr 2017 21:29:11 -0700, you wrote: >Do typical frequency counters start their gate in phase with the incoming signal? I guess the >answer would be, "It depends." I was just thinking about how I would program the STM32F7 >counter I am designing. > >btw, Gilbert, a local time-nut, sold me a 5335 today so I will be able to buiild one great one >out of the two I will have. > >Jerry