In STM32 Cube HAL, in interrupt mode (async),
2 bytes can be prepared in hardware registers without any read
(1 in regular register, the other in shift register),
but Only 1 RX byte can stored in hardware register, specially when there is no hardware FIFO.
If interrupt handling is fast enough, each read is made in parralele of the write.
But if interrupt handling is too long or is interrupted for too long,
it can happen that one read byte is lost (overrun).
For STM32F4, Tickless has been deactivated to avoid such issue.
For STM32L0, we don't want to deactivate tickless,
because those chips are specially design for lowpower.
So instead of removing SPI async mode,
we propose to change the HAL behavior specially for L0:
each byte is send only when previous read is performed.
Thus only 1 RX byte at a time which is saved in hardware register.
This prevent overrun, but it introduceS some latency between each byte send,
this is why it is not applied to all STM32 families.
- default value is the same as before patch
- system_stm32l0xx.c file is copied to family level with all other ST cube files
- specific clock configuration is now in a new file: system_clock.c (target level)
When we want to activate USE_FULL_ASSERT macro in STM32 CUBE, there is a
need to have the assert map to MBED.
The easiest way to have this definition in a single place for all STM32
HAL and LL files using it, is to add a specific header file where the
porting to MBED is done.
Before this patch, many warnings like below were generated
during compilation with ArmCC
[Warning] lwip_ethernet.h@57,0: #3135-D: attribute does not apply to any entity
This happens here as ``--gnu`` option of ArmCC is being used, which
enables the GNU compiler extensions that the ARM compiler supports.
This is solve by adding a extra check on __CCARM .
In case of sequential transmit / receive, there is a need to:
- not use the reload option
- generate a new START on each new transaction
This applies to all HAL supporting the IP version V2.
Alexandre Bourdiol
Martin Kojtal
jeromecoutant
bcostm
Laurent MEUNIER
Jimmy Brisson
Alexis ROCHE
Sam Grove
Christopher Haster