Class InterruptController

Nested Relationships

Nested Types

Inheritance Relationships

Base Type

Derived Types

Class Documentation

class InterruptController : public Peripheral

Generic interrupt controller.

It manages an interrupt vector table that the CPU can access to know if a interrupt routine should be executed. Each interrupt vector may be allocated by a interrupt handler which controls the raise (or cancellation) of the interrupt.

The arbitration of priorities between vectors is left to concrete sub-classes.

See also

AVR_InterruptHandler

Subclassed by ArchAVR_IntCtrl, ArchXT_IntCtrl

Public Types

enum SignalId

Values:

enumerator Signal_StateChange

Signal ID for indicating that the state of an interrupt has changed. index is the vector index.

enum State

Values:

enumerator State_Raised

The interrupt is raised.

enumerator State_Cancelled

The interrupt is cancelled.

enumerator State_Acknowledged

The interrupt is acknowledged by the CPU and it’s about to jump to the corresponding vector.

enumerator State_Returned

The CPU returned from the interrupt routine.

enumerator State_RaisedFromSleep

The interrupt is raised after leaving a sleep mode where it was masked.

enumerator State_Reset

The interrupt is reset because the MCU is reset.

Public Functions

explicit InterruptController(unsigned int vector_count)

Construct the controller with the given vector table size

virtual void reset() override

Virtual method called when the device is reset. Note that resetting I/O registers is only necessary here if their reset value is not zero.

virtual bool ctlreq(ctlreq_id_t req, ctlreq_data_t *data) override

Virtual method called for a CTL request. The method must return true if the request has been processed.

virtual void sleep(bool on, SleepMode mode) override

Virtual method called when the device enters or exits a sleep mode.

Parameters:

  • on – true when entering a sleep mode, false when exiting it.

  • mode – one of the enum SleepMode values

inline bool cpu_has_irq() const

Used by the CPU to do a quick test whether an interrupt is raised.

Returns:

true if there is an IRQ raised.

inline IRQ_t cpu_get_irq() const

Used by the CPU to interrogate the controller whether an interrupt is raised.

If a valid vector is returned and the Global Interrupt Enable flag is set, the CPU initiates a jump to the corresponding routine.

Returns:

a vector index if there is an IRQ raised, AVR_INTERRUPT_NONE if not.

void cpu_ack_irq()

Used by the CPU to acknowledge the IRQ obtained with cpu_get_irq().

virtual void cpu_reti()

Called by the CPU when returning from an ISR (executing a RETI instruction).

The base implementation calls update_irq to determine the next vector to be given to the CPU.

Public Static Attributes

static constexpr IRQ_t NO_INTERRUPT = {AVR_INTERRUPT_NONE, 0, false}

Protected Functions

inline bool interrupt_raised(int_vect_t vector) const

Interrupt state getter.

inline int_vect_t intr_count() const

Interrupt table size getter.

void set_interrupt_raised(int_vect_t vector, bool raised)

Interrupt state setter.

virtual void cpu_ack_irq(int_vect_t vector)

Called by the CPU when it acknowledges a vector, i.e. it is about to execute the vector address in the flash.

The base implementation calls the ACK handler of the vector and raise the signal with the “Acknowledged” state.

virtual IRQ_t get_next_irq() const = 0

Abstract method indicating which vector should be executed next. Architecture specific behaviors can be implemented here to take into account priority arbitration between vectors.

Note

implementations should assume the GIE flag is set.

Returns:

IRQ to be executed next or NO_INTERRUPT

void update_irq()

Update the controller, by storing the next vector to be given to the CPU

struct IRQ_t

Structure returned by the interrupt controller to the CPU containing the information of the interrupt to process.

Public Members

int_vect_t vector

Vector index.

flash_addr_t address

Address (in bytes) of the interrupt vector.

bool nmi

Non-maskable (by GIE) indicator flag.