Hi,
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).
It's simply
BCSCTL1 = 0x07;
BCSCTL2 = 0x80;
DCOCTL = 0xe0;
at the beginning of main.
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.
I don't need the full temperature range and it works to 2.7 V. To avoid
brownouts/blackouts main is started with supply voltage detection to
avoid trying to start the quartz oszillator with not enough voltage.
Regards
Rolf F.
