more interrupts
clocks:
mclk
smclk
aclk

direct software control of clocks
can enable/disable at will
there are lots of default clock settings, found in the slides for 3/2
clock can drift based on voltage and temp

temp coeff can be reduced by using external resistor
you can apparently mix clocks in the DCO to get something in between

DCO is open loop, close with sw+hw
ref freq can be used to measure dcoclk
init/periodic software set and stabilizes dcoclk over ref clock
programmable 100K-5M and stable over voltage and temp

got code last class to setup clocks


watchdog timer:
pat the dog, clear bit so counter doesn't expire
bit 4: 0 for wd, 1 for timer mode
5: selects f() of nmi pin, 0 for reset input, 1 for edge-sensitive nmi input
6:selects rising or falling edge (0,1) for nmi triggers
7:stops op of watchdog counter, 0 for wd fully active, 1 for...it's in the notes
lots of examples in the slides

we have several ports to play with, up to 6
lots of fun