External IRQ (r_icu)

Functions
fsp_err_t	R_ICU_ExternalIrqOpen (external_irq_ctrl_t *const p_api_ctrl, external_irq_cfg_t const *const p_cfg)
fsp_err_t	R_ICU_ExternalIrqEnable (external_irq_ctrl_t *const p_api_ctrl)
fsp_err_t	R_ICU_ExternalIrqDisable (external_irq_ctrl_t *const p_api_ctrl)
fsp_err_t	R_ICU_ExternalIrqCallbackSet (external_irq_ctrl_t *const p_api_ctrl, void(*p_callback)(external_irq_callback_args_t *), void const *const p_context, external_irq_callback_args_t *const p_callback_memory)
fsp_err_t	R_ICU_ExternalIrqClose (external_irq_ctrl_t *const p_api_ctrl)

Detailed Description

Driver for the ICU peripheral on RA MCUs. This module implements the External IRQ Interface.

Overview

The Interrupt Controller Unit (ICU) controls which event signals are linked to the NVIC, DTC, and DMAC modules. The R_ICU software module only implements the External IRQ Interface. The external_irq interface is for configuring interrupts to fire when a trigger condition is detected on an external IRQ pin.

Note

Multiple instances are used when more than one external interrupt is needed. Configure each instance with different channels and properties as needed for the specific interrupt.

Features

• Supports configuring interrupts for IRQ pins on the target MCUs
  • Enabling and disabling interrupt generation.
  • Configuring interrupt trigger on rising edge, falling edge, both edges, or low level signal.
  • Enabling and disabling the IRQ noise filter.
• Supports configuring a user callback function, which will be invoked by the HAL module when an external pin interrupt is generated.

Configuration

Build Time Configurations for r_icu

The following build time configurations are defined in fsp_cfg/r_icu_cfg.h:

Configuration	Options	Default	Description
Parameter Checking	Default (BSP) Enabled Disabled	Default (BSP)	If selected code for parameter checking is included in the build.

Configurations for Input > External IRQ (r_icu)

This module can be added to the Stacks tab via New Stack > Input > External IRQ (r_icu). Non-secure callable guard functions can be generated for this module by right clicking the module in the RA Configuration tool and checking the "Non-secure Callable" box.

Configuration	Options	Default	Description
Name	Name must be a valid C symbol	g_external_irq0	Module name.
Channel	Value must be an integer between 0 and 15	0	Specify the hardware channel.
Trigger	MCU Specific Options		Select the signal edge or state that triggers an interrupt.
Digital Filtering	MCU Specific Options		Select if the digital noise filter should be enabled.
Digital Filtering Sample Clock (Only valid when Digital Filtering is Enabled)	MCU Specific Options		Select the clock divider for the digital noise filter.
Callback	Name must be a valid C symbol	NULL	A user callback function can be provided here. If this callback function is provided, it is called from the interrupt service routine (ISR) each time the IRQn triggers
Pin Interrupt Priority	MCU Specific Options		Select the PIN interrupt priority.

Clock Configuration

The ICU peripheral module doesn't require any specific clock settings.

Note

The digital filter uses PCLKB as the clock source for sampling the IRQ pin.

Pin Configuration

The pin for the external interrupt channel must be configured as an input with IRQ Input Enabled.

Limitation

Pin configuration does not show conflicts when same IRQ is used by multiple pins.

Usage Notes

Digital Filter

The digital filter is used to reject trigger conditions that are too short. The trigger condition must be longer than three periods of the filter clock. The filter clock frequency is determined by PCLKB and the external_irq_pclk_div_t setting.

MIN_PULSE_WIDTH = EXTERNAL_IRQ_PCLKB_DIV / PCLKB_FREQUENCY * 3

DMAC/DTC

When using an External IRQ pin to trigger a DMAC/DTC transfer, the External IRQ pin must be opened before the transfer instance is opened.

Examples

Basic Example

This is a basic example of minimal use of the ICU in an application.

#define ICU_IRQN_PIN    BSP_IO_PORT_02_PIN_06
#define ICU_IRQN        6

/* Called from icu_irq_isr */
void external_irq_callback (external_irq_callback_args_t * p_args)
{
    (void) p_args;

    g_external_irq_complete = 1;
}

void simple_example ()
{
    /* Example Configuration */
    external_irq_cfg_t icu_cfg =
    {
        .channel          = ICU_IRQN,
        .trigger          = EXTERNAL_IRQ_TRIG_RISING,
        .filter_enable    = false,
        .clock_source_div = EXTERNAL_IRQ_CLOCK_SOURCE_DIV_1,
        .p_callback       = external_irq_callback,
        .p_context        = 0,
        .ipl              = 0,
        .irq              = (IRQn_Type) 0,
    };

    /* Configure the external interrupt. */
    fsp_err_t err = R_ICU_ExternalIrqOpen(&g_icu_ctrl, &icu_cfg);
    assert(FSP_SUCCESS == err);

    /* Enable the external interrupt. */
    /* Enable not required when used with ELC or DMAC. */
    err = R_ICU_ExternalIrqEnable(&g_icu_ctrl);
    assert(FSP_SUCCESS == err);

    while (0 == g_external_irq_complete)
    {
        /* Wait for interrupt. */
    }
}

Data Structures
struct	icu_instance_ctrl_t

---

Data Structure Documentation

icu_instance_ctrl_t

struct icu_instance_ctrl_t

ICU private control block. DO NOT MODIFY. Initialization occurs when R_ICU_ExternalIrqOpen is called.

Data Fields
uint32_t	open
	Used to determine if channel control block is in use.
IRQn_Type	irq
	NVIC interrupt number.
uint8_t	channel
	Channel.
void const *	p_context

Field Documentation

p_context

void const* icu_instance_ctrl_t::p_context

Placeholder for user data. Passed to the user callback in external_irq_callback_args_t.

Function Documentation

R_ICU_ExternalIrqOpen()

fsp_err_t R_ICU_ExternalIrqOpen	(	external_irq_ctrl_t *const	p_api_ctrl,
		external_irq_cfg_t const *const	p_cfg
	)

Configure an IRQ input pin for use with the external interrupt interface. Implements external_irq_api_t::open.

The Open function is responsible for preparing an external IRQ pin for operation.

Return values

FSP_SUCCESS	Open successful.
FSP_ERR_ASSERTION	One of the following is invalid: p_ctrl or p_cfg is NULL
FSP_ERR_ALREADY_OPEN	The channel specified has already been opened. No configurations were changed. Call the associated Close function to reconfigure the channel.
FSP_ERR_IP_CHANNEL_NOT_PRESENT	The channel requested in p_cfg is not available on the device selected in r_bsp_cfg.h.
FSP_ERR_INVALID_ARGUMENT	p_cfg->p_callback is not NULL, but ISR is not enabled. ISR must be enabled to use callback function.
FSP_ERR_UNSUPPORTED	An input argument is not supported by selected mode.

Note

This function is reentrant for different channels. It is not reentrant for the same channel.

R_ICU_ExternalIrqEnable()

fsp_err_t R_ICU_ExternalIrqEnable

(

external_irq_ctrl_t *const

p_api_ctrl

)

Enable external interrupt for specified channel at NVIC. Implements external_irq_api_t::enable.

Return values

FSP_SUCCESS	Interrupt Enabled successfully.
FSP_ERR_ASSERTION	The p_ctrl parameter was null.
FSP_ERR_NOT_OPEN	The channel is not opened.
FSP_ERR_IRQ_BSP_DISABLED	Requested IRQ is not defined in this system

R_ICU_ExternalIrqDisable()

fsp_err_t R_ICU_ExternalIrqDisable

(

external_irq_ctrl_t *const

p_api_ctrl

)

Disable external interrupt for specified channel at NVIC. Implements external_irq_api_t::disable.

Return values

FSP_SUCCESS	Interrupt disabled successfully.
FSP_ERR_ASSERTION	The p_ctrl parameter was null.
FSP_ERR_NOT_OPEN	The channel is not opened.
FSP_ERR_IRQ_BSP_DISABLED	Requested IRQ is not defined in this system

R_ICU_ExternalIrqCallbackSet()

fsp_err_t R_ICU_ExternalIrqCallbackSet	(	external_irq_ctrl_t *const	p_api_ctrl,
		void(*)(external_irq_callback_args_t *)	p_callback,
		void const *const	p_context,
		external_irq_callback_args_t *const	p_callback_memory
	)

Updates the user callback and has option of providing memory for callback structure. Implements external_irq_api_t::callbackSet

Return values

FSP_SUCCESS	Callback updated successfully.
FSP_ERR_ASSERTION	A required pointer is NULL.
FSP_ERR_NOT_OPEN	The control block has not been opened.
FSP_ERR_NO_CALLBACK_MEMORY	p_callback is non-secure and p_callback_memory is either secure or NULL.

R_ICU_ExternalIrqClose()

fsp_err_t R_ICU_ExternalIrqClose

(

external_irq_ctrl_t *const

p_api_ctrl

)

Close the external interrupt channel. Implements external_irq_api_t::close.

Return values

FSP_SUCCESS	Successfully closed.
FSP_ERR_ASSERTION	The parameter p_ctrl is NULL.
FSP_ERR_NOT_OPEN	The channel is not opened.