Key Matrix (r_kint)

Functions
fsp_err_t	R_KINT_Open (keymatrix_ctrl_t *const p_api_ctrl, keymatrix_cfg_t const *const p_cfg)
fsp_err_t	R_KINT_Close (keymatrix_ctrl_t *const p_api_ctrl)
fsp_err_t	R_KINT_Enable (keymatrix_ctrl_t *const p_api_ctrl)
fsp_err_t	R_KINT_Disable (keymatrix_ctrl_t *const p_api_ctrl)

Detailed Description

Driver for the KINT peripheral on RA MCUs. This module implements the Key Matrix Interface.

Overview

The KINT module configures the Key Interrupt (KINT) peripheral to detect rising or falling edges on any of the KINT channels. When such an event is detected on any of the configured pins, the module generates an interrupt.

Features

• Detect rising or falling edges on KINT channels
• Callback for notifying the application when edges are detected on the configured channels

Configuration

Build Time Configurations for r_kint

The following build time configurations are defined in fsp_cfg/r_kint_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 > Key Matrix (r_kint)

This module can be added to the Stacks tab via New Stack > Input > Key Matrix (r_kint).

Configuration	Options	Default	Description
General
Name	Name must be a valid C symbol	g_kint0	Module name.
Input
Key Interrupt Flag Mask	MCU Specific Options		Select channels to enable.
Interrupts
Trigger Type	Falling Edge Rising Edge	Rising Edge	Specifies if the enabled channels detect a rising edge or a falling edge. NOTE: either all channels detecting a rising edge or all channels detecting a falling edge.
Callback	Name must be a valid C symbol	kint_callback	A user callback function can be provided. If this callback function is provided, it will be called from the interrupt service routine (ISR) each time the IRQ triggers.
Key Interrupt Priority	MCU Specific Options		Select the key interrupt priority.

Clock Configuration

The KINT peripheral runs on PCLKB.

Pin Configuration

The KRn pins are key switch matrix row input pins.

Usage Notes

Connecting a Switch Matrix

The KINT module is designed to scan the rows of a switch matrix where each row is connected to a number of columns through switches. A periodic timer (or other mechanism) sets one column pin high at a time. Any switches that are pressed on the driven column cause a rising (or falling) edge on the row pin (KRn) causing an interrupt.

Note

In applications where multiple keys may be pressed at the same time it is recommended to put a diode inline with each switch to prevent ghosting.

Handling Multiple Pins

When an edge is detected on multiple pins at the same time, a single IRQ will be generated. A mask of all the pins that detected an edge will be passed to the callback.

Examples

Basic Example

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

static volatile uint32_t g_channel_mask;
static volatile uint32_t g_kint_edge_detected = 0U;

/* Called from key_int_isr */
void r_kint_callback (keymatrix_callback_args_t * p_args)
{
    g_channel_mask       = p_args->channel_mask;
    g_kint_edge_detected = 1U;
}

void r_kint_example ()
{
    /* Configure the KINT. */
    fsp_err_t err = R_KINT_Open(&g_kint_ctrl, &g_kint_cfg);

    /* Handle any errors. This function should be defined by the user. */
    assert(FSP_SUCCESS == err);

    /* Enable the KINT. */
    err = R_KINT_Enable(&g_kint_ctrl);
    assert(FSP_SUCCESS == err);

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

Data Structures
struct	kint_instance_ctrl_t

---

Data Structure Documentation

kint_instance_ctrl_t

struct kint_instance_ctrl_t

Channel instance control block. DO NOT INITIALIZE. Initialization occurs when keymatrix_api_t::open is called.

Function Documentation

R_KINT_Open()

fsp_err_t R_KINT_Open	(	keymatrix_ctrl_t *const	p_api_ctrl,
		keymatrix_cfg_t const *const	p_cfg
	)

Configure all the Key Input (KINT) channels and provides a handle for use with the rest of the KINT API functions. Implements keymatrix_api_t::open.

Return values

FSP_SUCCESS	Initialization was successful.
FSP_ERR_ASSERTION	One of the following parameters may be NULL: p_cfg, or p_ctrl or the callback.
FSP_ERR_ALREADY_OPEN	The module has already been opened.
FSP_ERR_IP_CHANNEL_NOT_PRESENT	The channel mask is invalid.

R_KINT_Close()

fsp_err_t R_KINT_Close

(

keymatrix_ctrl_t *const

p_api_ctrl

)

Clear the KINT configuration and disable the KINT IRQ. Implements keymatrix_api_t::close.

Return values

FSP_SUCCESS	Successful close.
FSP_ERR_ASSERTION	The parameter p_ctrl is NULL.
FSP_ERR_NOT_OPEN	The module is not opened.

R_KINT_Enable()

fsp_err_t R_KINT_Enable

(

keymatrix_ctrl_t *const

p_api_ctrl

)

This function enables interrupts for the KINT peripheral after clearing any pending requests. Implements keymatrix_api_t::enable.

Return values

FSP_SUCCESS	Interrupt enabled successfully.
FSP_ERR_ASSERTION	The p_ctrl parameter was null.
FSP_ERR_NOT_OPEN	The peripheral is not opened.

R_KINT_Disable()

fsp_err_t R_KINT_Disable

(

keymatrix_ctrl_t *const

p_api_ctrl

)

This function disables interrupts for the KINT peripheral. Implements keymatrix_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.