As reported by MBED user Fran6Jack:
I2C bus are usually 5V tolerant on all STM32 processor.
If an external device on the I2C bus requires 5V operation,
we usually acheive it by using 5V external pull-ups on the bus.
Since signaling uses open-drain output on I2C for both signal SCL and SDA
any 5V tolerant MCU will work on a 5V I2C bus. Having pull-up activated on a 5V externally pull bus, cause the pin to clamp on the STM32 die diode and could damage the IC (There is a note in STM32 datasheet specifying this issue).
It is understood by all the community that I2C bus should always be
externally pulled by physical resistor. I2C initialization should then
be ALWAYS OpenDrainNoPull by default.
Up to now, this I2C driver was setting pull up by default as it helps
basic testing, like 1 master and 1 slave, conencted with 2 wires without
any external pull ups. This will not work anymore after this commit and
applications tests or examples needs to be modified to explicitely
configure pull ups ... But it is safer to follow reference manual
guidelines.
Decrease the interrupt stack from 2k down to 1k so there is enough
ram to build all the tests with tickless enabled. In general, targets
should not need an interrupt stack greater than 1k with mbed-os.
Rather than Unlocking flash during flash object creation, and leaving
the flash possibly continuously unlocked a(s object might bever be freed),
we decide to Unlock then Lock again at each erase or program call.
Fixing regression introduced in commit
"Ticker: add fire interrupt now function".
In above mentioned commit, the management of timestamp being in the past
has been moved to higher layer (hal/mbed_ticker_api.c), but the reset of
oc_int was missing when implementing the new us_ticker_fire_interrupt
function - which is fixed now.
After reset the MCR register content needs to be restored so we're
introducing the can_registers_init function to be called at the first
init stage, but also after reset. We also store the can frequency to
go through the initialisation phase again.
In order to apply the same mode in case of reset, we store the current
requested mode in the HAL structure.
To make storage in a single place, we also change can_monitor to call
can_mode function as they actually acting on same registers.
Instead of a static object, this will make driver
instantiation more robust and allow to re-use init
configuration on a need basis.
The CANName struct member is actually the CAN registers base address,
which is now available in the CanHandle.Instance field, so we don't need
CANName anymore.
Jimmy Brisson
Pavel Sorejs
bcostm
andreas.larsson
jeromecoutant
Martin Kojtal
Laurent MEUNIER
Russ Butler
Kevin Gilbert
Jan Jongboom
gorazd