Basic Extended CAN2. More...

#include <modm/platform/can/can_2.hpp>

Inheritance diagram for modm::platform::Can2:

Public Types
enum	Mode : uint32_t { Normal = 0, ListenOnly = CAN_BTR_SILM, LoopBack = CAN_BTR_LBKM, ListenOnlyLoopBack = CAN_BTR_SILM \| CAN_BTR_LBKM }

enum	BusState : uint8_t { BusState::Connected = 0, BusState::ErrorWarning = 1, BusState::ErrorPassive = 2, Off = 3 }

Static Public Member Functions
template<class... Signals>
static void	connect (Gpio::InputType inputType=Gpio::InputType::Floating)

template<class SystemClock , bitrate_t bitrate = kbps(125), percent_t tolerance = pct(1)>
static bool	initialize (uint32_t interruptPriority, Mode startupMode=Mode::Normal, bool overwriteOnOverrun=true)

static void	setMode (Mode mode)

static void	setAutomaticRetransmission (bool retransmission)

static bool	isMessageAvailable ()

static bool	getMessage (can::Message &message, uint8_t *filter_id=nullptr)

static bool	isReadyToSend ()

static bool	sendMessage (const can::Message &message)

static uint8_t	getReceiveErrorCounter ()

static uint8_t	getTransmitErrorCounter ()

static BusState	getBusState ()

static void	enableStatusChangeInterrupt (uint32_t interruptEnable, uint32_t interruptPriority)

static void	acknowledgeInterruptFlag ()

template<uint64_t available, uint64_t requested, percent_t tolerance>
static void	assertBaudrateInTolerance ()

template<double available, double requested, percent_t tolerance>
static void	assertDurationInTolerance ()

static void	configurePurpose ()
	configures a peripheral for a specific purpose

template<class... Signals>
static void	connect ()

static bool	getInterruptFlag ()
	Read an interrupt flag.

static bool	getMessage (can::Message &message)
	Returns true if a message was copied into the message buffer.

static void	getParameter ()
	returns a parameter

template<class SystemClock , bitrate_t bitrate = 125_kbps, percent_t tolerance = 1_pct>
static void	initialize (Mode startupMode)

static void	initialize ()
	initializes the peripheral, must be called before use.

static void	setParameter ()
	sets a parameter

Static Public Attributes
static constexpr size_t	RxBufferSize = 32

static constexpr size_t	TxBufferSize = 32

Detailed Description

Basic Extended CAN2.

The Basic Extended CAN peripheral, named bxCAN, interfaces the CAN network. It supports the CAN protocols version 2.0A and B. It has been designed to manage a high number of incoming messages efficiently with a minimum CPU load.

Filter

For connectivity line devices there are 28 filter banks, i=0 .. 27, in other devices there are 14 filter banks i = 0 ..13.

The 28 filter banks for the connectivity line devices are shared between CAN1 and CAN2.

Configuration

You can set the buffer size using the tx_buffer and rx_buffer parameters.

Author: Fabian Greif fabian.greif@rwth-aachen.de

Member Enumeration Documentation

enum modm::Can::BusState : uint8_t

inheritedstrong

Enum Values	Documentation
Connected	This bit is set by hardware when the warning limit has been reached (Receive Error Counter or Transmit Error Counter ≥ 96).
ErrorWarning	This bit is set by hardware when the Error Passive limit has been reached (Receive Error Counter or Transmit Error Counter > 127).
ErrorPassive	This bit is set by hardware when it enters the bus-off state. The bus-off state is entered on TEC overflow, greater than 255

Member Function Documentation

static void modm::PeripheralDriver::acknowledgeInterruptFlag ( )

inheritedstatic

Acknowledge an interrupt flag.

We use acknowledge here, since it describes the intention rather than the actual implementation.

template<uint64_t available, uint64_t requested, percent_t tolerance>

static void modm::PeripheralDriver::assertBaudrateInTolerance ( )

inheritedinlinestatic

Since baudrates are usually generated by prescaling a system clock, only several distinct values can be generated. This method checks if the user requested baudrate is within error tolerance of the system achievable baudrate.

template<class... Signals>

static void modm::Can::connect ( )

inheritedstatic

Configures the Tx and Rx signals and connects them.

Template Parameters

Signals One Tx and one Rx signal are required and can be passed out-of-order.

void modm::platform::Can2::enableStatusChangeInterrupt	(	uint32_t	interruptEnable,
		uint32_t	interruptPriority
	)

static

Enable the error and status change interrupt.

Can be generated by the following events:

Error condition, for more details on error conditions please refer to the CAN Error Status register (CAN_ESR).
Wakeup condition, SOF monitored on the CAN Rx signal.
Entry into Sleep mode

You need to create you own interrupt handler for this interrupt. The interrupt handler has a fixed name:

MODM_ISR(CAN2_SCE)
{
    ...
 
    // e.g. Acknowledge interrupt
    CAN2->MSR = CAN_MSR_ERRI;
}

Parameters

interruptEnable	Upper 24-bit of the CAN_IER register. E.g.: CAN_IER_BOFIE CAN_IER_EPVIE ... See Reference Manual >> bxCAN >> CAN_IER Register
interruptPriority	Interrupt vector priority (0=highest to 15=lowest)

static uint8_t modm::platform::Can2::getReceiveErrorCounter ( )

inlinestatic

Get Receive Error Counter.

In case of an error during reception, this counter is incremented by 1 or by 8 depending on the error condition as defined by the CAN standard. After every successful reception the counter is decremented by 1 or reset to 120 if its value was higher than 128. When the counter value exceeds 127, the CAN controller enters the error passive state.

static uint8_t modm::platform::Can2::getTransmitErrorCounter ( )

inlinestatic

Get Transmit Error Counter.

template<class SystemClock , bitrate_t bitrate = 125_kbps, percent_t tolerance = 1_pct>

static void modm::Can::initialize ( Mode startupMode )

inheritedstatic

Initializes the hardware and sets the baudrate.

Template Parameters

SystemClock	the currently active system clock
bitrate	the desired bitrate in Hz
tolerance	the allowed relative tolerance for the resulting baudrate

template<class SystemClock , bitrate_t bitrate = kbps(125), percent_t tolerance = pct(1)>

static bool modm::platform::Can2::initialize	(	uint32_t	interruptPriority,
		Mode	startupMode = `Mode::Normal`,
		bool	overwriteOnOverrun = `true`
	)

nodiscardinlinestatic

Enables the clock for the CAN controller and resets all settings

Parameters

bitrate	CAN bitrate (defined in driver/connectivity/can/message.hpp)
interruptPriority	Interrupt vector priority (0=highest to 15=lowest)
overwriteOnOverrun	Once a receive FIFO is full the next incoming message will overwrite the previous one if `true` otherwise the incoming message will be discarded

Warning: Has to called after connect(), but before any other function from this class!

void modm::platform::Can2::setMode ( Mode mode )

static

The the operating mode.

Default after initialization is the normal mode.

The documentation for this class was generated from the following files:

can_2.hpp
can_2.cpp

Public Types

Static Public Member Functions

Static Public Attributes

Detailed Description

Filter

Configuration

Member Enumeration Documentation

Member Function Documentation