Teensy doesn't need to worry about overflows since all of
its timers are only 16-bit.
For PWM, the pulse width needs to be able to vary from 0..period+1
(pulse-width == period+1 corresponds to 100% PWM)
I couldn't test the 0xffffffff cases since we can't currently get a
period that big in python. With a prescaler of 0, that corresponds
to a freq of 0.039 (i.e. cycle every 25.56 seconds), and we can't
set that using freq or period.
I also tested both stmhal and teensy with floats disabled, which
required a few other code changes to compile.
These functions are generally 1 machine instruction, and are used in
critical code, so makes sense to have them inline.
Also leave these functions uninverted (ie 0 means enable, 1 means
disable) and provide macro constants if you really need to distinguish
the states. This makes for smaller code as well (combined with
inlining).
Applied to teensy port as well.
Because (for Thumb) a function pointer has the LSB set, pointers to
dynamic functions in RAM (eg native, viper or asm functions) were not
being traced by the GC. This patch is a comprehensive fix for this.
Addresses issue #820.
A big change. Micro Python objects are allocated as individual structs
with the first element being a pointer to the type information (which
is itself an object). This scheme follows CPython. Much more flexible,
not necessarily slower, uses same heap memory, and can allocate objects
statically.
Also change name prefix, from py_ to mp_ (mp for Micro Python).
Dave Hylands
Damien George
Paul Sokolovsky