Replace the thread used in the test case teardown with a Ticker to allow
testing with the bare metal profile. This Ticker is used to prevent the
watchdog from resetting the device during the final greentea
communication.
Extend the deepsleep wait up to 220% of the Watchdog timeout.
One of the current Watchdog timing requirements is to fire BEFORE twice
the timeout value, but at least one target (K64F) is expected to fire
EXACTLY at a doubled timeout value in deepsleep mode. This patch updates
the test to cope with a new deepsleep timing requirement.
Add a watchdog-kicking thread running in the background when the test
suite is handling a failed assertion. A single watchdog kick did not
provide enough time for the greentea communication if the watchdog
reset happened later than expected.
Update the watchdog timing requirements:
1. The watchdog should trigger at, or after the timeout value.
2. The watchdog should trigger before twice the timeout value.
Remove explicit calls to sleep.
* capitalize driver class name,
* reword test docs for the driver & HAL,
* capitalize Mbed name,
* reword the comments explaining the SERIAL_FLUSH_TIME_MS macro.
On NUMAKER_PFM_NANO130 target, WDT's clock source is fixed to LIRC, which is much
less accurate than other targets. Enlarge delta define to pass this test.