Hi With some micros you can play with the PWM outputs to get a bit faster than the instruction cycle would allow. There are always constraints (like binary division) on that as well.
Bob On Jul 24, 2012, at 5:21 PM, John Ackermann N8UR wrote: > TVB can give a better answer, but in general the number of clock cycles > required per instruction limits the minimum divide ratio. > > Tom whipped up a special PIC to get the highest possible output rate for a > set of tests we were doing, and given the 20 MHz maximum input clock, we got > about 800 kHz output. > > John > --- > > On 7/24/2012 1:05 PM, Chris Hoffman, KG6O wrote: >> John, >> >> That's interesting to me. What exactly are the actual structural limitations >> of [that] pic? >> >> -CH >> >> On Jul 24, 2012, at 7:55, John Ackermann N8UR <j...@febo.com> wrote: >> >>> Unfortunately, the TAPR T2-Mini divider >>> (http://www.tapr.org/kits_t2-mini.html) can't quite get to 1 MHz from 10 >>> MHz with the PIC divider chip due to limitations in the chip architecture. >>> >>> However, nothing says you couldn't "dead bug" in a decade divider chip in >>> place of the PIC, and let the T2-Mini provide the input conditioning, >>> output driver, voltage regulation, connectorization, etc. for you, making >>> it much a smaller project. >>> >>> John >>> ---- >>> >>> On 7/24/2012 8:18 AM, Chris Wilson wrote: >>>> >>>> >>>> 24/07/2012 13:14 >>>> >>>> My Racal Dana 9908 can take a 1 Mhz external reference. Inputting my >>>> Thunderbolt at 10 MHz works, but shifts the decimal point over. I am >>>> not sure if this has any other detrimental effects as to accuracy or >>>> other? What's the easiest way to have a 1 MHz reference from the >>>> Thunderbolt for this timer / counter please, yet retaining 10 Mhz for >>>> my other devices that want a 10MHz reference signal? Thanks. >>>> >>> >>> >>> _______________________________________________ >>> 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. >> > > > _______________________________________________ > 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.
