Quote Originally Posted by jmbanales21485 View Post
"Defining an OSC value has no effect on PULSIN. The resolution always changes with the actual oscillator speed." thanks
All this means is that pulsin will count as fast as the PIC is running.
An example...
Your statement is: Pause 1 and you've got DEFINE OSC 20 and a 20Mhz crystal. PBP adds in a delay loop, a few NOPs, etc, and you'll get a 1 millisecond pause.
Now, without changing the program, you switch over to a 4Mhz crystal and run the same program. The pause will be 5ms long because PBP figured you wanted a 1ms pause @ 20Mhz.
Same thing with SERIN/SEROUT, and a few other timing sensitive commands.

Pulsin is different...It runs just as fast as it can in a nice tight loop checking the pins as fast as it can. You can 'DEFINE OSC xx' all day and not change how fast pulsin runs. The only way you can change it is by changing the oscillator.

So, yes, for the best resolution with pulsin, you have to go with a faster clock speed.