There's no need to have these as separate functions, they just take up
unnecessary code space and combining them allows to factor common code, and
also allows to support arbitrary string descriptor indices.
The routine waits for the DMA to finish, which is signalled from a DMA IRQ
handler. Using WFI makes the CPU sleep while waiting for the IRQ to arrive
which decreases power consumption. To make it work correctly the check for
the change in state must be atomic and so IRQs must be disabled during the
check. The key feature of the Cortex MCU that makes this possible is that
WFI will exit when an IRQ arrives even if IRQs are disabled.
This patch adds in internal config value MICROPY_HW_ENABLE_HW_I2C that is
automatically configured, and enabled only if one or more hardware I2C
ports are defined in the mpconfigboard.h file. If none are defined then
the pyb.I2C class is excluded from the build, along with all supporting
code. The machine.I2C class will still be available for software I2C.
Disabling all hardware I2C on an F4 board saves around 10,000 bytes of code
and 200 bytes of RAM.
This is a low-cost evaluation kit board from ST based on the STM32
Nucleo-144 form factor. It uses the STM32F746ZG MCU in the LQFP144
package. The MCU has 1MB of flash and 320kB of System RAM.
Cortex-M7 runs at up to 216MHz.
This patch simplifies the str creation API to favour the common case of
creating a str object that is not forced to be interned. To force
interning of a new str the new mp_obj_new_str_via_qstr function is added,
and should only be used if warranted.
Apart from simplifying the mp_obj_new_str function (and making it have the
same signature as mp_obj_new_bytes), this patch also reduces code size by a
bit (-16 bytes for bare-arm and roughly -40 bytes on the bare-metal archs).
The legacy function pyb.repl_uart() is still provided and retains its
original behaviour (it only accepts a UART object). uos.dupterm() will now
accept any object with write/readinto methods. At the moment there is just
1 dupterm slot.
The W5200 and W5500 can support up to 80MHz so 42MHz (the maximum the
pyboard can do in its standard configuration) should be safe.
Tested to give around 1050000 kbytes/sec TCP download speed on a W5500,
which is about 10% more than with the previous SPI speed of 21MHz.
Which Wiznet chip to use is a compile-time option: MICROPY_PY_WIZNET5K
should be set to either 5200 or 5500 to support either one of these
Ethernet chips. The driver is called network.WIZNET5K in both cases.
Note that this commit introduces a breaking-change at the build level
because previously the valid values for MICROPY_PY_WIZNET5K were 0 and 1
but now they are 0, 5200 and 5500.
Header files that are considered internal to the py core and should not
normally be included directly are:
py/nlr.h - internal nlr configuration and declarations
py/bc0.h - contains bytecode macro definitions
py/runtime0.h - contains basic runtime enums
Instead, the top-level header files to include are one of:
py/obj.h - includes runtime0.h and defines everything to use the
mp_obj_t type
py/runtime.h - includes mpstate.h and hence nlr.h, obj.h, runtime0.h,
and defines everything to use the general runtime support functions
Additional, specific headers (eg py/objlist.h) can be included if needed.
The timer prescaler is buffered by default, and this patch enables ARPE
which buffers the auto-reload register. With both of these registers
buffered it's now possible to smoothly change the timer's frequency and
have a smoothly varying PWM output.
