The AON RTC CH1 event handler aims to schedule the next compare event on the next 512 RTC counter boundary. However, the current calculation of "now" takes place too early within the interrupt handler. In some cases, this results in the next event getting scheduled too soon in the future or on some extreme cases even in the past.
AON RTC compare events cannot happen within 2 SCLK_LF cycles after a clearance (4 RTC ticks in the 16.16 format). Thus, if the next 512 boundary is too soon (5 ticks for margin), we skip it altogether. When this happens, etimers that would have expired on the skipped tick will expire 1 tick later instead. Skipping a tick has no negative impact on our s/w clock counter, since this is always derived directly from the hardware counter.
* The clock interrupt must be scheduled relative to the last interrupt, not relative to the current time (which may have progressed significantly)
* clock_time() must increase continuously, so that code that may be spinning around clock_time() will make progress, not only after each interrupt
Added a mode, configurable by the CONTIKI_WATCHDOG_CONF_LOCK_BETWEEN_USE
macro, which locks the WDT register between uses so as to prevent
any accidental modifications
According to the TRM, the WDT does not produce a reset until it
expires twice. After expiring the WDT will set the INT flag if it
is unset, and reset the MCU if INT is already set.
Before this patch, watchdog_periodic() only un-sets the INT flag. This
means that the behaviour of watchdog_periodic is underministic in that
the value of the countdown timer will be different depending on
when the function was called.
This patch fixes this behaviour by also reloading the timout value.
This commit:
* Moves all cpu files from cpu/cc26xx to cpu/cc26xx-cc13xx
* Bumps the CC26xxware submodule to the latest TI release
* Adds CC13xxware as a submodule
* Adds support for sub-ghz mode / IEEE 802.15.4g
* Splits the driver into multiple files for clarity. We now have the following structure:
* A common module that handles access to the RF core, interrupts etc
* A module that takes care of BLE functionality
* A netstack radio driver for IEEE mode (2.4GHz)
* A netstack radio driver for PROP mode (sub-ghz - multiple bands)
This commit also adds tick suppression functionality, applicable to all chips of the CC26xx and CC13xx families. Instead waking up on every clock tick simply to increment our software counter, we now only wake up just in time to service the next scheduled etimer. ContikiMAC-triggered wakeups are unaffected.
Laslty, this commit also applies a number of minor changes:
* Addition of missing includes
* Removal of stub functions
* Removal of a woraround for a CC26xxware bug that has now been fixed
