This class supports SPI bus controller mode, with blocking transfers.
SPI device numbers start at 0, to comply with the pinout of the Teensy
boards. With the configured clock frequency the fastest baud rate is
33MHz. For messages longer 16 bytes DMA is used. The class uses the
existing framework with extmod/machine_spi.c.
Extended driver options:
- drive=n with n being between 1 and 6 or PIN.POWER_1 to PIN.POWER_6.
Since the pins used by the SPI are fixed, no Pin settings can be made.
Thus the drive option is added allowing to control ringing and crosstalk
on the connection.
- gap_ns=nnnnn is the time between sent data items in a frame given in ns.
Default is 2 clock cycles.
The implementation uses the LPUARTx devices. Up to 8 UARTs can be used,
given that the pins are accessible. E.g. 8 on Teensy 4.1, 5 on
MIMXRT1020_EVK.
For Tennsy 4.0 and 4.1 the UART numbers are as printed on the pinout 1..N.
The MIMXRT10xx-EVK boards have only one UART named, which gets the number
1. All other UART are assigned to different Pins:
MIMXRT1010-EVK:
D0/D1 UART 1
D6/D7 UART 2
A0/D4 UART 3
MIMXRT1020-EVK:
D0/D1 UART 1
D6/D9 UART 2
D10/D12 UART 3
D14/D15 UART 4
A0/A1 UART 5
MIMXRT1050-EVK, MIMXRT1060-EVK, MIMXRT1064-EVK:
D0/D1 UART 1
D7/D6 UART 2
D8/D9 UART 3
A1/A0 UART 4
This commit adds full support for a filesystem on all boards, with a block
device object mimxrt.Flash() and uos.VfsLfs2 enabled.
Main changes are:
- Refactoring of linker scripts to accomodate reserved area for VFS. VFS
will take up most of the available flash. 1M is reserved for code. 9K is
reserved for flash configuration, interrupts, etc.
- Addition of _boot.py with filesystem init code, called from main.c.
- Definition of the mimxrt module with a Flash class in modmimxrt.[ch].
- Implementation of a flash driver class in mimxrt_flash.c. All flashing
related functions are stored in ITCM RAM.
- Addition of the uos module with filesystem functions.
- Implementation of uos.urandom() for the sake of completeness of the uos
module.
It uses sample code from CircuitPython supplied under MIT license, which
uses the NXP SDK example code.
Done in collaboration with Philipp Ebensberger aka @alphaFred who
contributed the essential part to enable writing to flash while code is
executing, among other things.
- modified pin type from pin_obj_t to machine_pin_obj_t
- created machine_pin.c
- implemented basic version of make-pins.py to genertate pins.c/.h files
automatically; the only alternate function currently supported is GPIO
- added af.csv files for all supported MCUs
- replaced pins.c/pins.h files with pin.csv for all boards
- implemented on/off/high/low/value/init methods
- Implemented IN/OUT/OPEN_DRAIN modes
- modified LDFLAGS for DEBUG build to get usefull .elf file for debugging
Signed-off-by: Philipp Ebensberger
