r f wrote:
2) start a high speed crystal so everything else goes fast.
without a quartz you have approx. 4,8 MHz at 3.0 V from the DCO (checked
but only after you set it to the highest frequency (altough thats very
quick to do, compared to a crystal startup). i think to remeber that the
startup value for the DCO after a reset is around 700kHz.
with toggling a port and an oscilloscope) and if you don´t overclock you
can take only an 8 MHz quartz (which is stable overclocking at only 3 V)
- the difference is not huge.
it's probably not a good idea if you need to full temerature range, but
i use 8MHz at 3V too for my desktop projects and never had problems.
chris
