On some targets like STM family boards with LPTIM enabled an interrupt is triggered on counter rollover.
We need special handling for cases when next_match_timestamp < start_timestamp (interrupt is to be fired after rollover).
In such case after first wake-up we need to reset interrupt and go back to sleep waiting for the valid one.
On some targets like STM family boards with LPTIM enabled there is a required delay (~100 us) before we are able to reprogram LPTIM_COMPARE register back to back.
This is handled by the low level lp ticker wrapper which uses LPTIM_CMPOK interrupt. CMPOK fires when LPTIM_COMPARE register can be safely reprogrammed again.
This means that on these platforms we have additional interrupt (CMPOK) fired always ~100 us after programming lp ticker.
Since this interrupt wake-ups the board from the sleep we need to go to sleep after CMPOK is handled.
Background:
There is an errata in LPTIM specification that explains that CMP Flag
condition is not an exact match (COUNTER = MATCH) but rather a
comparison (COUNTER >= MATCH).
As a consequence the interrupt is firing early than expected when
programing a timestamp after the 0xFFFF wrap-around.
In order to
work-around this issue, we implement the below work-around.
In case timestamp is after the work-around, let's decide to program the
CMP value to 0xFFFF, which is the wrap-around value. There would anyway be
a wake-up at the time of wrap-around to let the OS update the system time.
When the wrap-around interrupt happen, OS will check the current time and
program again the timestamp to the proper value.
Automatically enable entropy injection when the NV Seed feature is
requested on PSA targets. Add a warning note describing the state of the
current implementation of the entropy injection API.
Fixes#10720
Correct C++14 operation of the alloc wrappers requires us to define
custom sized delete operators.
Their presence won't cause any problem for people compiling as C++03 or
C++11.
Add unified syntax directives to make the atomic assembler work when GCC
is building for M23.
GCC actually uses unified syntax when compiling C code, but puts
`.syntax divided` before each piece of inline assembly when targetting
Thumb-1 type devices like M0 and M23 for backwards compatibility. We can
overcome this with our own `.syntax unified`. The command-line option
`-masm-syntax-unified` intended to override this globally has been
broken from GCC 6 to 8.0.
Building binaries with MicroLib and Arm compiler 6 has been failing
because of a bug in Arm compiler 6. The compiler introduces a
symbol, `__scanf_mbtowc`, which is not present in MicroLib C library.
The present commit adds a weak reference to the symbol to allow a
successful linkage. This is a temporary fix until the bug in the
compiler is fixed. It should be removed after the compiler bug is fixed.
Added logic to lock deep sleep when USB is initialized to prevent malfunctioning. This is consistent with the other drivers. See PR ARMmbed/mbed-os#9879
Przemyslaw Stekiel
Martin Kojtal
Jaeden Amero
Alexander Zilberkant
Chris Trowbridge
Mirela Chirica
Kevin Bracey
Antti Kauppila
Hugues Kamba
Laurent Meunier
Ari Parkkila
Filip Jagodzinski
ccli8
jeromecoutant
Teppo Järvelin
Ronny Liu
George Psimenos
George Beckstein