* Only enable TX by default.
* Add some magic for RX handling. When an input handler is registered:
* Automatically enable RX-related and interrupts
* Automatically lock the SERIAL PD on under all power modes
* Automatically enable the UART clock under sleep and deep sleep
* Automatically undo all of the above when the input handler becomes NULL
* As a result, modules / examples that need UART RX no longer need to clock the UART and manipulate the SERIAL PD. They simply have to specify an input handler
* Don't automatically power on the UART whenever the CM3 is active
* Before accessing the UART, make sure it is powered and clocked
* Avoid falling edge glitches
* Fix garbage characters / Explicitly wait for UART TX to complete
* Implement new style of PD locks
* Use our own shutdown sequence rather than the one provided by cc26xxware
* Shutdown from within the interrupt that requested it. This allows shutdown to take place even if the code is stuck in a loop somewhere else
* Improve DCDC/GLDO/uLDO switching logic
* Explicitly handle oscillators and retentions
Instead of using a separate data structure to request that a PD remain powered during deep sleep,
we do the same within the main LPM data structure through an additional field.
This allows us to maintain only one linked list of LPM modules and overall improves code clarity
This tutorial was written for the older implementation of CoAP, and
while it may be possible to update it, the directions include URLs and
repos that no longer exist, so it's better to just remove it.
Only the interrupt flags that have been handled must be cleared.
Otherwise, if a new interrupt occurs after the interrupt statuses are
read and before they are cleared, then it is discarded without having
been handled. This issue was particularly likely with two interrupt
trigger conditions occurring on different pins of the same port in a
short period of time.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau.dev@gmail.com>