The new period needs to be saved before the duty cycle is updated as
the period is used in pwmout_write function.
Also presclaer shall better be initiliazed properly.
- removing redundancy as discussed in PR #2087:
- in target.json the core option can have only this values : "Cortex-M0", "Cortex-M0+", "Cortex-M1", "Cortex-M3", "Cortex-M4", "Cortex-M7", "Cortex-A9" - Cortex-M4F and Cortex-M7F removed
- in target.json an additional fpu option with values: "single" and "double" can be used
- build and export scripts are changed to handle this
- tested (compiling, running on hardware) with nucleo_f767 (cortex-m7 with double precision fpu), nucleo_f746 (cortex-m7 with single precision fpu), nucleo_f446 and nucleo_l467 (cortex-m4 with single precision fpu), teensy31 (cortex-m4 without fpu - only build test), nucleo_l073 (cortex-m0)
- singletest results are added to PR #2087 comments
- creating new core name Cortex_M7F_DP for a target with a double precision fpu
- adding new core name to arm.py to set compiler/linker flags to a double precision fpu when configured in target.json
- up to now: gcc wrote flag for a double precision fpu -> target with STM32F746 didn't run when using double variables - mcu has only single precision fpu
- changing gcc.py to use single precision for Cortex-M7 und double precision for Cortex_M7F_DP
tested with NUCLEO_F746, NUCLEO_F767 and build.py+make.py and exporting with project.py + compiling/flashing
- iar.py need a similar extention - I didn't change that yet because
- did not run at the moment - python exception
- currently worked on in PR #1948
The host-test resets the target by sending a UART break. After this, it takes some
time for the target to come back up. Without this timeout, the __sync packet
sent by greentea would not be retransmitted by the interface chip (i.e. it would never
reach the target). Testing on different devices indicates that 2 seconds delay
is sufficient for the device to reset and the __sync packet to reach the target.
Prevent mismatch between _owner and peripheral configuration. In the previous
implementation, the following code would leave the peripheral in an inconsistent
state:
```
SPI spi1(...); // _owner is NULL, peripheral config is 1
spi1.transfer(...); // _owner is 1, config is 1
SPI spi2(...); // _owner is 1, config is 2
spi1.transfer(...) // 1 thinks it still owns peripheral, doesn't reconfigure
```