If RTC is already running at boot then it's left alone. Otherwise, RTC is
started at boot but startup function returns straight away. RTC startup
is then finished the first time it is used. Fallback to LSI if LSE fails
to start in a certain time.
Also included:
MICROPY_HW_CLK_LAST_FREQ
hold pyb.freq() parameters in RTC backup reg
MICROPY_HW_RTC_USE_US
option to present datetime sub-seconds in microseconds
MICROPY_HW_RTC_USE_CALOUT
option to enable RTC calibration output
CLK_LAST_FREQ and RTC_USE_CALOUT are enabled for PYBv1.0.
The DFU bootloader on the ST32F7 chip changes the clocksource
for various possible boot sources (UART1, UART3, I2C1-3).
This commit resets those clock sources back to their cold
reset values.
Eg pyb.freq(120000000) sets the CPU to 120MHz. The frequency can be set
at any point in the code, and can be changed as many times as you like.
Note that any active timers will need to be reconfigured after a freq
change.
Valid range is 24MHz to 168MHz (but not all freqs are supported). The
code maintains a 48MHz clock for the USB at all times and it's possible
to change the frequency at a USB REPL and keep the REPL alive (well,
most of the time it stays, sometimes it resets the USB for some reason).
Note that USB does not work with pyb.freq of 24MHz.
This patch updates ST's HAL to the latest version, V1.3.0, dated 19 June
2014. Files were copied verbatim from the ST package. Only change was
to suppress compiler warning of unused variables in 4 places.
A lot of the changes from ST are cosmetic: comments and white space.
Some small code changes here and there, and addition of F411 header.
Main code change is how SysTick interrupt is set: it now has a
configuration variable to set the priority, so we no longer need to work
around this (originall in system_stm32f4xx.c).
Blanket wide to all .c and .h files. Some files originating from ST are
difficult to deal with (license wise) so it was left out of those.
Also merged modpyb.h, modos.h, modstm.h and modtime.h in stmhal/.
Tobias Badertscher
T S
Dave Hylands
Damien George