This RNG passes many of the Diehard tests and also the AIS31 test suite.
The RNG is quite slow, delivering 200bytes/s.
Tested on boards with and without a crystal.
It turned out that the result of calling ticks_us() was always either odd
or even, depending on some internal state during boot. So the us-counter
was set to a 2 MHz input and the result shifted by 1. The counting period
is still long enough, since internally a (now) 63 bit value is used for us.
By using the phase jitter between the DFLL48M clock and the FDPLL96M clock.
Even if both use the same reference source, they have a different jitter.
SysTick is driven by FDPLL96M, the us counter by DFLL48M. As a random
source, the us counter is read out on every SysTick and the value is used
to accumulate a simple multiply, add and xor register. According to tests
it creates about 30 bit random bit-flips per second. That mechanism will
pass quite a few RNG tests, has a suitable frequency distribution and
serves better than just the time after boot to seed the PRNG.
Allowing to increase the clock a little bit to 54Mhz. Not much of a gain,
but useful for generating a RNG entropy source from the jitter between
DFLL48M and FDPLL96M.
Remove two SPARKFUN_SAMD51_THINGS_PLUS pin definitions. There were
definitions of TXD and RXD, but these pins do not exist on the board. They
were only shown in the schematics.
Also remove any reference to LED_. This is just a text change, no
functional change.
For compatibility with other ports. Code increase up to ~1250 bytes for
SAMD21. The feature is configurable via MICROPY_PY_MACHINE_PIN_BOARD_CPU
in case flash memory is tight.
Before, both uwTick and mp_hal_ticks_ms() were used as clock source. That
assumes, that these two are synchronous and start with the same value,
which may be not the case for all ports. If the lag between uwTick and
mp_hal_ticks_ms() is larger than the timer interval, the timer would either
rush up until the times are synchronous, or not start until uwTick wraps
over.
As suggested by @dpgeorge, MICROPY_SOFT_TIMER_TICKS_MS is now used in
softtimer.c, which has to be defined in a port's mpconfigport.h with
the variable that holds the SysTick counter.
Note that it's not possible to switch everything in softtimer.c to use
mp_hal_ticks_ms() because the logic in SysTick_Handler that schedules
soft_timer_handler() uses (eg on mimxrt) the uwTick variable directly
(named systick_ms there), and mp_hal_ticks_ms() uses a different source
timer. Thus it is made fully configurable.
This drops the `.cpu` directive from the ARM gchelper_*.s files. Having
this directive breaks the linker when targeting older CPUs (e.g. `-mthumb
-mthumb-interwork` for `-mcpu=arm7tdmi`). The actual target CPU should be
determined by the compiler options.
The exact CPU doesn't actually matter, but rather the supported assembly
instruction set. So the files are renamed to *_thumb1.s and *thumb2.s to
indicate the instruction set support instead of the CPU support.
Signed-off-by: David Lechner <david@pybricks.com>
ADC: The argument of vref=num is an integer. Values for num are:
SAMD21:
0 INT1V 1.0V voltage reference
1 INTVCC0 1/1.48 Analog voltage supply
2 INTVCC1 1/2 Analog voltage supply (only for VDDANA > 2.0V)
3 VREFA External reference
4 VREFB External reference
SAMD51:
0 INTREF internal bandgap reference
1 INTVCC1 Analog voltage supply
2 INTVCC0 1/2 Analog voltage supply (only for VDDANA > 2.0v)
3 AREFA External reference A
4 AREFB External reference B
5 AREFC External reference C (ADC1 only)
DAC: The argument of vref=num is an integer. Suitable values:
SAMD21:
0 INT1V Internal voltage reference
1 VDDANA Analog voltage supply
2 VREFA External reference
SAMD51:
0 INTREF Internal bandgap reference
1 VDDANA Analog voltage supply
2 VREFAU Unbuffered external voltage reference (not buffered in DAC)
4 VREFAB Buffered external voltage reference (buffered in DAC).
Changes in this commit:
- Do not deinit IRQ when uart.deinit() is called with an inactive object.
- Remove using it for the finaliser. There is another machanism for soft
reset, and it is not needed otherwise.
- Do not tag the UART buffers with MP_STATE_PORT, it is not required.
Clearing the DRE flag for the transmit interrupt at the end of a
uart.write() also cleared the RXC flag disabling the receive interrupt.
This commit also changes the flag set/clear mechanism in the driver for SPI
as well, even if it did not cause a problem there. But at least it saves a
few bytes of code.
Applies to both SPI and I2C. The underflow caused high baudrate settings
resulting in the lowest possible baudrate. The overflow resulted in
erratic baudrates, not just the lowest possible.
If USB CDC is connected and the board sends data, but the host does not
receive the data, the device locks up. This is fixed in this commit by
having a timeout of 500ms, after which time the transmission is skipped.
Most of the content of README.md became obsolete and was replaced by the
documentation of MicroPython. Instead, README.md now shows build
instructions like the other ports.
Including the uasyncio scripts and the drivers for DHT, DS18x20 and
onewire. The uasyncio scripts need about 8k of flash and are not included
for the SAMD21 boards by default.
Protect SerCom (UART, SPI, I2C) objects from getting freed by the GC when
they go out of scope without being deinitialized. Otherwise the ISR of a
Sercom may access an invalid data structure.
Any update of freq or duty_cycle requires the previous PWM cycle to be
finished. Otherwise the new settings are not accepted.
Other changes in this commit:
- Report the set duty cycles even when the PWM is not yet started.
- pwm.freq(0) stops the pwm device, instead of raising an expception.
- Clear the duty cycle value cache on soft reset.
Changes are:
- Remove the LED_Pxxx definitions from pins.csv, now that the LED class is
gone.
- Remove the '-' lines.
- Add default lines for USB and SWCLK, SWDIO.
Pin numbers are now the MCU port numbers in the range:
PA0..PA31: 0..31
PB0..PB31: 32..63
PC0..PC31: 64..95
PD0..PD31: 96..127
Pins can be denoted by the GPIO port number, the name as defined in
pins.csv or a string in the form Pxnn, like "PA16" or "PD03".
The pins.c and pins.h files are now obsolete. The pin objects are part of
the AF table.
As result of a simplification, the code now supports using pin names or
numbers instead of pin objects for modules like UART, SPI, PWM, I2C, ADC,
pininfo.
This removes the difference in the time.ticks_us() range between SAMD21 and
SAMD51.
The function mp_hal_ticks_us_64() is added and used for:
- SAMD51's mp_hal_ticks_us and mp_hal_delay_us().
For SAMD21, keep the previous methods, which are faster.
- mp_hal_ticks_ms() and mp_hal_tick_ms_64(), which saves some bytes
and removes a potential race condition every 50 days.
Also set the us-counter for SAMD51 to 16 MHz for a faster reading of the
microsecond value.
Note: With SAMD51, mp_hal_ticks_us_64() has a 60 bit range only, which is
still a long time (~36000 years).
Methods implemented are:
- rtc.init(date)
- rtc.datetime([new_date])
- rtc.calibration(value)
The presence of this class can be controlled by MICROPY_PY_MACHINE_RTC. If
the RTC module is used, the time module uses the RTC as well.
For boards without a 32kHz crystal, using RTC makes no sense, since it will
then use the ULP32K oscillator, which is not precise at all. Therefore, it
will by default only be enabled for boards using a crystal, but can be
enabled in the respective mpconfigboard.h.
Using the stream method for uart.flush().
uart.txdone() returns True, if the uart not busy, False otherwise.
uart.flush() waits until all bytes have been transmitted or a timeout
triggers. The timeout is determined by the buffer size and the baud rate.
Also fix two inconsistencies when not using txbuf:
- Report in ioctl as being writeable if there is room in the tx buffer,
only if it is configured.
- Print the txbuf size if configured.
Instead of being hard-coded, and then it works for all MCUs.
That fits except for a Sparkfun SAMD51 Thing Plus (known) bug, which uses
192k - 4 as magic address. Therefore, that address is set as well to avoid
a problem when this bug is fixed by Sparkfun.
Which just sets the CPU clock to 200kHz and switches the peripheral clock
off. There are two modes:
machine.lightsleep(duration_ms)
and
machine.lightsleep()
In any mode any configured pin.irq() event will terminate the sleep.
Current consumption in lightsleep for some boards:
- 1.5 - 2.5 mA when supplied trough an active USB
(Seeed XIAO w/o power LED, Adafruit ItsyBitsy)
- 0.8 - 2 mA when supplied through Gnd/+5V (Vusb)
(Seeed XIAO w/o power LED, Adafruit ItsyBitsy)
- < 1 mA for SAMD51 when supplied trough a battery connector
(Sparkfun Thing SAMD51 plus)
Related change: move the calls to SysTick_Config() into set_cpu_freq(). It
is required after each CPU freq change to have ticks_ms run at the proper
rate.
Tested with a SD card connected to a SAMD51 board. The SEEED WIO terminal
has a SD-Card reader built-in.
Also a side change to remove a few obsolete lines from Makefile.
The range is 1MHz - 48 MHz. Note that below 8 MHz there is no USB support.
The frequency will be set to an integer fraction of 48 MHz. And after
changing the frequency, the peripherals like PWM, UART, I2C, SPI have to be
reconfigured.
Current consumption e.g. of the Seeed Xiao board at 1 MHz is about 1.5 mA,
mostly caused by the on-board LED (green LED with 1k resistor at 3.3V).
The value given for machine.freq(f) is extend to the range of 1_000_000 to
200_000_000. Frequencies below 48 MHz will be forced to an integer
fraction of 48 MHz. At frequencies below 8 MHz USB is switched off. The
power consumption e.g. of ADAFRUIT_ITSYBITSY_M4_EXPRESS drops to about
1.5 mA at 1 MHz.
Since the peripheral frequency is dropped as well, timing e.g. of PWM,
UART, I2C and SPI is affected and frequency/baud rate has to set again
after a frequency change below 48 MHz.
This makes it so that all a port needs to do is set the relevant variables
and "include extmod.mk" and doesn't need to worry about adding anything to
OBJ, CFLAGS, SRC_QSTR, etc.
Make all extmod variables (src, flags, etc) private to extmod.mk.
Also move common/shared, extmod-related fragments (e.g. wiznet, cyw43,
bluetooth) into extmod.mk.
Now that SRC_MOD, CFLAGS_MOD, CXXFLAGS_MOD are unused by both extmod.mk
(and user-C-modules in a previous commit), remove all uses of them from
port makefiles.
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
Removes the need for the port to add anything to OBJS or SRC_QSTR.
Also makes it possible for user-C-modules to differentiate between code
that should be processed for QSTR vs other files (e.g. helpers and
libraries).
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
It now prints lines like:
Pin("D9", mode=IN, pull=PULL_UP, GPIO=PA07)
or
LED("LED")
showing for consistency the names as given in pins.csv. For pins, the GPIO
numer is printed as well for a reference.
Porting PR #8040 by @hoihu to SAMD, following the commit
5873390226.
One small addition: before executing keyboard interrupt, the input buffer
is cleared.
Changes are:
- The pin-af-table-SAMDxx.csv file are moved to the mcu directories with
the name as pin-af-table.csv.
- The handling in Makefile and pin_af.c is simplified.
Two new compile flags are:
MICROPY_HW_DFLL_USB_SYNC: Effective only if DFLL48 does not run from the
crystal. It will synchronize the DFLL48M clock with the USB's SOF pulse.
If no USB is connected, it will fall back to open loop mode. The DFLL48M
clock is then pretty precise, but with a higher clock jitter at SAMD51
devices.
MICROPY_HW_MCU_OSC32KULP: Effective only if the devics uses a crystal as
clock source. Run the MCU clock from the ULP 32kHz oszillator instead of
the crystal. This flag was added to cater for a interference problem of
the crystal and Neopixel/Debug pins at Adafruit FEATHER Mx boards, which
causes the board to crash. Drawback: ticks_ms() and time.time() vs. than
ticks_us() and the peripherals like PWM run at not synchronous clocks.
Changes are:
- Set the feature level for each MCU: CORE features for SAMD21, and EXTRA
features for SAMD51.
- Remove all definitions that are included in the core feature level.
- Keep the default settings for feature level and float, to make the choice
obvious.
The SAMD21 implementation is an adaption of @jimmo's code for STM32Lxx.
The only changes are the addresses and names of the port registers and the
timing parameters.
SAMD21: The precision is about +/-25ns at 48MHz clock frequency. The first
two cycles are about 40-60 ns longer than set. But still good enough to
drive a neopixel device.
SAMD51: The precision is about +/-30ns at 120MHz clock frequency. Good
enough to drive a neopixel device.
And use mp_hal_ticks_us() for SAM21's mp_hal_ticks_cpu(). The SAMD21 has
no CYCCNT register, and the SysTick register has only a 1 ms span (== 48000
count range).
Fixes are:
- Pin definitions for ADAFRUIT_FEATHER_Mx_EXPRESS and
ADAFRUIT_ITSYBITSY_M4_EXPRESS.
- For ADAFRUIT_ITSYBITSY_M0_EXPRESS, change the MISO/MOSI name.
- For MINISAM_M4, add the default SPI pins.
- For boards with 32k crystal, add the XOSC32K setting.
It can be enabled/disabled by a configuration switch. The code size
increase is 308 bytes, but it requires RAM space for buffers, the larger
UART object and root pointers.
Allowing to set a time and retrieve the time. It is based on systick_ms()
with the precision of the MCU clock. Unless that is based on a crystal,
the error seen was about 0.5% at room temperature.
It suuports 1 channel @ 10 bit for SAMD21, 2 channels @ 12 bit for SAMD51.
Instantiation by:
dac = machine.DAC(ch) # 0 or 1
Method write:
dac.write(value)
The output voltage range is 0..Vdd.
By reducing the methods to on(), off(), toggle() and call, and using the
method implementation of the machine.Pin class.
The code size reduction is 756 byte.
All board pins that have UART's assigned can be used. Baud rate range is
75 Baud to ~2 MBaud.
No flow control yet, and only RX is buffered. TX buffer and flow control
may be added later for SAMD51 with its larger RAM and Flash.
Its API conforms to the docs. There are 16 IRQ channels available, which
will be used as assignable to the GPIO numbers. In most cases, the irq
channel is GPIO_no % 16.
Changes are:
- Have two separate tables for SAM21 and SAMD51.
- Use a short table for SAMD21.
- Add a comment to each line telling what it's for, making further use
easier.
- Add preliminary handlers/entries for PendSV, EIC and Sercom. These will
be replaced later when the respecitve modules are added.
Features are:
- 3 to 5 different frequency groups.
- Freq range of 1Hz - 24 MHz.
- Duty rate stays stable on freq change.
Keyword options to the PWM constructor:
- device=n Select a specific PWM device. If no device is specified, a free
device is chosen, if available at that pin.
- freq=nnnn
- duty_u16=nnnn
- duty_ns=nnnn
- invert=True/False Allowing two outputs on the same device/channel to have
complementary signals.
If both freq and duty are provided, PWM output will start immediately.
Pins at the same device have the same frequency. If the PWM output number
exceeds the number of channels at the PWM device, the effctive channel_no
is output_no % channel_count. So with a channel count of 4, output 7 is
assigned to channel 3. Pins at a certain channel have the same frequency
and duty rate, but may be seperately inverted.
With the method read_u16(). Keyword arguments of the constructor are:
- bits=n The resolution; default is 12.
- average=n The average of samples, which are taken and cumulated. The
default value is 16. Averaging by hw is faster than averaging
in code.
The ADC runs at a clock freq 1.5 MHz. A single 12 bit conversion takes
8 microseconds.
The pin af table is a representation of the MUX table from the data sheet.
It provides information for each pin about the supported device functions.
That information is needed by pin.irq, machine.ADC, machine.PWM,
machine.UART, machine.SPI and machine.I2C. For each of these, the table
tells for each pin, which device number, af number and pad number is
assigned. Using the table gives a straight, uniform access to the
information, where the benefit outweights the size of the table, which is
not that large.
The tables are MCU-specific. It is not required to tell for each board,
which and where each of the above devices is available. That makes addding
boards easy.
Note: The information for DAC and I2S was not included, since it affects
only a few pins.
robert-hh
David Lechner
Jim Mussared
Damien George
iabdalkader