modelPartialMcuCore

Programmable core without its sync point: Python program, electrical stage of each pin, power-on - the boards instantiate McuCore, which adds the sync point, cf. requirements.md decisions "Refactoring du socle des cartes" and "Radios micro:bit"

Extends from PartialMcuSettings (User parameters of a microcontroller (program, file system, execution time, debugging, electrical stages of the pins) - declared once, shared by the boards (MCU, RPi_Pico, MicroBit_v2) and their core Internal.Boards.McuCore).

Information

The programmable core, minus its sync point: embedded Python interpreter (PyRuntime), one electrical stage Internal.Boards.PinBridge per pin, power-on logic. The boards instantiate McuCore, which adds the sync point (PyRuntime_sync). Its parameters are those of the board that contains it (Internal.Boards.PartialMcuSettings), plus the pin table (nPins, pinIds, pinCaps, boardProfile) set by the board.

Pins pin[nPins]: push-pull outputs fed by vdd — their high level is the voltage of vdd, and their current is drawn from it.
Supply vdd/gnd: the core draws ICore while supplied.
Power-on: powerGood = vdd above VPowerOn (down to VPowerOff, hysteresis) and run high (internal pull-up, may stay unconnected). The program starts at the first supplied sync point, time.ticks_ms() counting from there; a later loss stops it for good (no restart), pins in high impedance.
ADC reference vref: high impedance input.
Temperature sensor (hasTempSensor): an extra ADC channel at the end of the pin table (pseudo-pin 30, ADC(4) on the pico profile), 0.706 V at 27 °C, −1.721 mV/°C.

See requirements.md, decisions "Carte Raspberry Pi Pico et alimentation" and "Refactoring du socle des cartes".

Parameters

Type	Name	Default	Description
Modelica.Units.SI.Time	tickPeriod (from PartialMcuSettings)	0.1	Period of the minimal sync point (output freshness if the script never sleeps)
Integer	nPins		Number of pins of the core (external pins, internal pins of the board, on-board LED) - at most 31 (MAX_PINS on the C side, minus the temperature sensor)
Integer[nPins]	pinIds		GPIO number of each pin, as written in the script
Integer[nPins]	pinCaps		Capabilities of each pin: sum of 1 = digital (Pin, PWM), 2 = wired to a connector (UART, I2C, I2CTarget), 4 = ADC input
String	boardProfile	"generic"	Board profile read by the machine shim: "generic" (MCU), "pico" (RPi_Pico) or "microbit" (MicroBit_v2)
Boolean	hasTempSensor	false	On-chip temperature sensor, read by machine.ADC(4) on the pico profile
Modelica.Units.NonSI.Temperature_degC	dieTemperature	27	Temperature of the chip, read by the temperature sensor
Modelica.Units.SI.Current	ICore	0.02	Current drawn from vdd by the core and its flash while supplied (pins excluded)
Modelica.Units.SI.Voltage	VPowerOn	1.8	Voltage of vdd above which the core starts (power-on reset)
Modelica.Units.SI.Voltage	VPowerOff	1.6	Voltage of vdd below which a running core stops for good (brown-out)
Modelica.Units.SI.Resistance	RRunPullUp	50e3	Internal pull-up of the RUN pin to vdd
String	instanceName	getInstanceName()	Name shown in the log and given to the copy of the flash: that of the board containing the core, set by it
Python script
String	scriptPath (from PartialMcuSettings)	Modelica.Utilities.Files.loadResource("modelica://MicroPythonMCU/Resources/Scripts/MCU/demo.py")	Path of the user script (.py) - with an active file system, run after boot.py instead of main.py; empty = main.py from the flash
Boolean	addScriptDirToPath (from PartialMcuSettings)	true	Make the .py files next to the script importable (e.g. import my_module) - mimics the real Pico (flash root folder on sys.path)
String	libraryPath (from PartialMcuSettings)	""	Optional: a .py file from a shared library folder to make importable (the folder containing this file is added to the module search path) - leave empty if unused
File system › Simulated flash
Boolean	fsEnabled (from PartialMcuSettings)	false	Enable the file system (simulated flash) - disabled: open() and os raise OSError
String	fsSource (from PartialMcuSettings)	""	Initial image of the flash (folder: data, boot.py, main.py, lib/), copied at each simulation and never modified - any file of the folder, the folder path or a modelica:// URI; empty = blank flash, only the script runs
String	fsWorkspace (from PartialMcuSettings)	"."	Workspace: folder where each simulation creates its copy, named <instance>_<FS name>_<date>_<time> (created if missing) - "." or relative path = from the simulation folder; full path of the copy shown in the log
Boolean	fsOpenExplorer (from PartialMcuSettings)	true	Open Windows Explorer on the copy at the end of the simulation
Execution time
Modelica.Units.SI.Time	gpioOpTime (from PartialMcuSettings)	5e-6	Execution time of a pin access (Pin.value(), on(), off()): two writes without sleep() give a pulse of this width (bit-banging) - order of magnitude of MicroPython on RP2040; 0 = instantaneous accesses
Modelica.Units.SI.Time	hangWarningTime (from PartialMcuSettings)	10	Real (wall-clock) time after which a warning is logged if the script does not let the simulation advance (loop without sleep() nor pin access, or with gpioOpTime = 0) - the simulation keeps waiting; 0 = no warning
Debugging
Boolean	debugEnabled (from PartialMcuSettings)	false	Debug the program with VS Code: at the start of the simulation, the microcontroller waits until VS Code attaches (debugpy, Run and Debug > attach to localhost:debugPort); simulated time stays frozen while the program is paused - one microcontroller per model
Integer	debugPort (from PartialMcuSettings)	5678	Local TCP port on which the debugger (debugpy) listens - the port of the VS Code attach configuration
Electrical › Logic levels
Modelica.Units.SI.Voltage	VOL (from PartialMcuSettings)	Interfaces.VOL	Logic low voltage
Modelica.Units.SI.Voltage	VIH (from PartialMcuSettings)	Interfaces.VIH	Threshold above which an input reads high
Modelica.Units.SI.Voltage	VIL (from PartialMcuSettings)	Interfaces.VIL	Threshold below which an input reads low
Electrical › Output stages
Modelica.Units.SI.Resistance	ROut (from PartialMcuSettings)	Interfaces.ROut	Output series resistance (drive strength)
Electrical › Input stages
Modelica.Units.SI.Resistance	RPullUp (from PartialMcuSettings)	Interfaces.RPull	Internal pull-up resistor to the supply, switched on by Pin(n, mode, Pin.PULL_UP) and by I2C() on SCL/SDA
Modelica.Units.SI.Resistance	RPullDown (from PartialMcuSettings)	Interfaces.RPull	Internal pull-down resistor to GND, switched on by Pin(n, mode, Pin.PULL_DOWN)
Modelica.Units.SI.Conductance	GOff (from PartialMcuSettings)	Interfaces.GOff	Leakage of a pin that does not drive its line (input, released I2C line), towards GND: 1e-9 S = 1 GOhm

Connectors

Type	Name	Description
Modelica.Electrical.Analog.Interfaces.PositivePin[nPins]	pin	Pins of the core, in the order of pinIds
Modelica.Electrical.Analog.Interfaces.PositivePin	vdd	Supply of the core and of its pins (IOVDD): high level of the outputs, pull-ups, consumption ICore
Modelica.Electrical.Analog.Interfaces.NegativePin	gnd	Ground
Modelica.Electrical.Analog.Interfaces.PositivePin	vref	Reference voltage of the ADC: read_u16() = 65535 at this voltage
Modelica.Electrical.Analog.Interfaces.PositivePin	run	Enable (RUN), pulled up to vdd inside the core: to ground, the core is stopped for good - may stay unconnected
Interfaces.DisplayLinkOutput	Display0	Logical link to an educational display peripheral (machine.Display(0).write())

Components

Type	Name	Description
Boolean	powerGood	The core is supplied (vdd above the power-on threshold, RUN high): its program starts the first time this becomes true and stops for good when it falls back. start = false: pins in high impedance during the initialization, where they are all inputs anyway (see pre(powerGood) below)
Boolean	supplyOk	vdd above the power-on threshold, with hysteresis
Boolean	runHigh	RUN high