KEYSCAN#

Example#

The following example demonstrates how to configure and use the KEYSCAN module to detect key presses on a keypad matrix.

// Global variables for key press tracking
volatile bool key_pressed = false;
volatile uint8_t detected_key = 0xFF;

// Interrupt handler for key press detection
void KEYSCAN_IRQHandler(void)
{
  uint32_t flags = sl_hal_keyscan_get_interrupts();

  if (flags & KEYSCAN_IF_KEY) {
    // Read the pressed key data
    uint32_t key_data = KEYSCAN->KEYDATA;
    uint8_t row = (key_data & _KEYSCAN_KEYDATA_ROW_MASK) >> _KEYSCAN_KEYDATA_ROW_SHIFT;
    uint8_t col = (key_data & _KEYSCAN_KEYDATA_COL_MASK) >> _KEYSCAN_KEYDATA_COL_SHIFT;

    // Calculate key index (assuming 3 columns)
    detected_key = row * 3 + col;
    key_pressed = true;

    // Clear the interrupt flag
    sl_hal_keyscan_clear_interrupts(KEYSCAN_IF_KEY);
  }
}

// Example of configuring and using KEYSCAN
void keyscan_example(void)
{
  // Configure KEYSCAN with custom settings
  sl_hal_keyscan_init_t keyscan_init = SL_HAL_KEYSCAN_INIT_DEFAULT;

  // Configure for a 3x4 keypad
  keyscan_init.column_number = 3;
  keyscan_init.row_number = 4;

  // Increase debounce delay to 20ms for improved reliability
  keyscan_init.debounce_delay = SL_HAL_KEYSCAN_DELAY_20MS;

  // Initialize KEYSCAN with our configuration
  sl_hal_keyscan_init(&keyscan_init);

  // Enable KEY interrupt
  sl_hal_keyscan_enable_interrupts(KEYSCAN_IEN_KEY);

  // Enable NVIC interrupt for KEYSCAN
  sl_interrupt_manager_enable_irq(KEYSCAN_IRQn);

  // Enable KEYSCAN peripheral
  sl_hal_keyscan_enable();
  sl_hal_keyscan_wait_sync();

  // Start keypad scanning
  sl_hal_keyscan_start_scan();

  // At this point, the KEYSCAN peripheral will automatically scan the keypad
  // and generate interrupts when keys are pressed. The interrupt handler will
  // process these events.

  // Main application code would go here
  // ...

  // When done with scanning, clean up
  sl_hal_keyscan_stop_scan();
  sl_hal_keyscan_disable_interrupts(KEYSCAN_IEN_KEY);
  sl_hal_keyscan_clear_interrupts(KEYSCAN_IF_KEY);
  sl_hal_keyscan_disable();
  sl_hal_keyscan_wait_ready();
  sl_hal_keyscan_reset();
  sl_hal_keyscan_wait_ready();
}

Modules#

sl_hal_keyscan_init_t

Enumerations#

enum

sl_hal_keyscan_delay_t {

SL_HAL_KEYSCAN_DELAY_2MS = 0

SL_HAL_KEYSCAN_DELAY_4MS

SL_HAL_KEYSCAN_DELAY_6MS

SL_HAL_KEYSCAN_DELAY_8MS

SL_HAL_KEYSCAN_DELAY_10MS

SL_HAL_KEYSCAN_DELAY_12MS

SL_HAL_KEYSCAN_DELAY_14MS

SL_HAL_KEYSCAN_DELAY_16MS

SL_HAL_KEYSCAN_DELAY_18MS

SL_HAL_KEYSCAN_DELAY_20MS

SL_HAL_KEYSCAN_DELAY_22MS

SL_HAL_KEYSCAN_DELAY_24MS

SL_HAL_KEYSCAN_DELAY_26MS

SL_HAL_KEYSCAN_DELAY_28MS

SL_HAL_KEYSCAN_DELAY_30MS

SL_HAL_KEYSCAN_DELAY_32MS

}

KEYSCAN configuration delay values.

Functions#

void

sl_hal_keyscan_init(const sl_hal_keyscan_init_t *init)

Initializes KEYSCAN module.

void

sl_hal_keyscan_enable(void)

Enables KEYSCAN module.

void

sl_hal_keyscan_disable(void)

Disables KEYSCAN module.

void

sl_hal_keyscan_wait_ready(void)

Waits for the KEYSCAN to complete resetting or disabling procedure.

void

sl_hal_keyscan_wait_sync(void)

Waits for the KEYSCAN to complete all synchronization of register changes and commands.

void

sl_hal_keyscan_start_scan(void)

Starts KEYSCAN scan.

void

sl_hal_keyscan_stop_scan(void)

Stops the KEYSCAN scan.

void

sl_hal_keyscan_reset(void)

Restores KEYSCAN to its reset state.

uint32_t

sl_hal_keyscan_get_status(void)

Gets KEYSCAN STATUS register value.

void

sl_hal_keyscan_enable_interrupts(uint32_t flags)

Enables one or more KEYSCAN interrupts.

void

sl_hal_keyscan_disable_interrupts(uint32_t flags)

Disables one or more KEYSCAN interrupts.

void

sl_hal_keyscan_clear_interrupts(uint32_t flags)

Clears one or more pending KEYSCAN interrupts.

uint32_t

sl_hal_keyscan_get_interrupts(void)

Gets pending KEYSCAN interrupt flags.

uint32_t

sl_hal_keyscan_get_enabled_interrupts(void)

Gets enabled and pending KEYSCAN interrupt flags.

void

sl_hal_keyscan_set_interrupts(uint32_t flags)

Sets one or more pending KEYSCAN interrupts from Software.

Macros#

#define

SL_HAL_KEYSCAN_INIT_DEFAULT undefined

Suggested default values for KEYSCAN configuration structure.

Enumeration Documentation#

sl_hal_keyscan_delay_t#

sl_hal_keyscan_delay_t

KEYSCAN configuration delay values.

Enumerator
SL_HAL_KEYSCAN_DELAY_2MS	2 ms delay.
SL_HAL_KEYSCAN_DELAY_4MS	4 ms delay.
SL_HAL_KEYSCAN_DELAY_6MS	6 ms delay.
SL_HAL_KEYSCAN_DELAY_8MS	8 ms delay.
SL_HAL_KEYSCAN_DELAY_10MS	10 ms delay.
SL_HAL_KEYSCAN_DELAY_12MS	12 ms delay.
SL_HAL_KEYSCAN_DELAY_14MS	14 ms delay.
SL_HAL_KEYSCAN_DELAY_16MS	16 ms delay.
SL_HAL_KEYSCAN_DELAY_18MS	18 ms delay.
SL_HAL_KEYSCAN_DELAY_20MS	20 ms delay.
SL_HAL_KEYSCAN_DELAY_22MS	22 ms delay.
SL_HAL_KEYSCAN_DELAY_24MS	24 ms delay.
SL_HAL_KEYSCAN_DELAY_26MS	26 ms delay.
SL_HAL_KEYSCAN_DELAY_28MS	28 ms delay.
SL_HAL_KEYSCAN_DELAY_30MS	30 ms delay.
SL_HAL_KEYSCAN_DELAY_32MS	32 ms delay.

Function Documentation#

sl_hal_keyscan_init#

void sl_hal_keyscan_init (const sl_hal_keyscan_init_t * init)

Initializes KEYSCAN module.

Parameters

Type	Direction	Argument Name	Description
const sl_hal_keyscan_init_t *	[in]	init	A pointer to the KEYSCAN initialization structure variable.

sl_hal_keyscan_enable#

void sl_hal_keyscan_enable (void )

Enables KEYSCAN module.

Parameters

Type	Direction	Argument Name	Description
void	N/A

sl_hal_keyscan_disable#

void sl_hal_keyscan_disable (void )

Disables KEYSCAN module.

Parameters

Type	Direction	Argument Name	Description
void	N/A

Note

The disabling of the module could take some time. This function will not wait for the disabling to finish before returning. Use the function sl_hal_keyscan_wait_ready to wait for the module to be fully disable.

sl_hal_keyscan_wait_ready#

void sl_hal_keyscan_wait_ready (void )

Waits for the KEYSCAN to complete resetting or disabling procedure.

Parameters

Type	Direction	Argument Name	Description
void	N/A

sl_hal_keyscan_wait_sync#

void sl_hal_keyscan_wait_sync (void )

Waits for the KEYSCAN to complete all synchronization of register changes and commands.

Parameters

Type	Direction	Argument Name	Description
void	N/A

sl_hal_keyscan_start_scan#

void sl_hal_keyscan_start_scan (void )

Starts KEYSCAN scan.

Parameters

Type	Direction	Argument Name	Description
void	N/A

Note

This function will send a start command to the KEYSCAN peripheral. The sl_hal_keyscan_wait_sync function can be used to wait for the start command to be executed.
This function requires the KEYSCAN to be enabled.

sl_hal_keyscan_stop_scan#

void sl_hal_keyscan_stop_scan (void )

Stops the KEYSCAN scan.

Parameters

Type	Direction	Argument Name	Description
void	N/A

Note

This function will send a stop command to the KEYSCAN peripheral. The sl_hal_keyscan_wait_sync function can be used to wait for the stop command to be executed.
This function requires the KEYSCAN to be enabled.

sl_hal_keyscan_reset#

void sl_hal_keyscan_reset (void )

Restores KEYSCAN to its reset state.

Parameters

Type	Direction	Argument Name	Description
void	N/A

Note

The resetting of the module could take some time. This function will not wait for the resetting to finish before returning. Use the function sl_hal_keyscan_wait_ready to wait for the module to be fully reset.

sl_hal_keyscan_get_status#

uint32_t sl_hal_keyscan_get_status (void )

Gets KEYSCAN STATUS register value.

Parameters

Type	Direction	Argument Name	Description
void	N/A

Returns

Current STATUS register value.

sl_hal_keyscan_enable_interrupts#

void sl_hal_keyscan_enable_interrupts (uint32_t flags)

Enables one or more KEYSCAN interrupts.

Parameters

Type	Direction	Argument Name	Description
uint32_t	[in]	flags	KEYSCAN interrupt sources to enable. Use a set of interrupt flags OR-ed together to set multiple interrupt sources.

Note

Depending on the use, a pending interrupt may already be set prior to enabling the interrupt. To ignore a pending interrupt, consider using sl_hal_keyscan_clear_interrupts prior to enabling the interrupt.

sl_hal_keyscan_disable_interrupts#

void sl_hal_keyscan_disable_interrupts (uint32_t flags)

Disables one or more KEYSCAN interrupts.

Parameters

Type	Direction	Argument Name	Description
uint32_t	[in]	flags	KEYSCAN interrupt sources to disable. Use a set of interrupt flags OR-ed together to disable multiple interrupt sources.

sl_hal_keyscan_clear_interrupts#

void sl_hal_keyscan_clear_interrupts (uint32_t flags)

Clears one or more pending KEYSCAN interrupts.

Parameters

Type	Direction	Argument Name	Description
uint32_t	[in]	flags	KEYSCAN interrupt sources to clear. Use a set of interrupt flags OR-ed together to clear multiple interrupt sources.

sl_hal_keyscan_get_interrupts#

uint32_t sl_hal_keyscan_get_interrupts (void )

Gets pending KEYSCAN interrupt flags.

Parameters

Type	Direction	Argument Name	Description
void	N/A

Note

Event bits are not cleared by using this function.

Returns

Pending KEYSCAN interrupt sources. Returns a set of interrupt flags OR-ed together for multiple interrupt sources.

sl_hal_keyscan_get_enabled_interrupts#

uint32_t sl_hal_keyscan_get_enabled_interrupts (void )

Gets enabled and pending KEYSCAN interrupt flags.

Parameters

Type	Direction	Argument Name	Description
void	N/A

Useful for handling more interrupt sources in the same interrupt handler.

Note

Interrupt flags are not cleared by using this function.

Returns

Pending and enabled KEYSCAN interrupt sources. The return value is the bitwise AND of
- the enabled interrupt sources in KEYSCAN_IEN and
- the pending interrupt flags KEYSCAN_IF.

sl_hal_keyscan_set_interrupts#

void sl_hal_keyscan_set_interrupts (uint32_t flags)

Sets one or more pending KEYSCAN interrupts from Software.

Parameters

Type	Direction	Argument Name	Description
uint32_t	[in]	flags	KEYSCAN interrupt sources to set to pending. Use a set of interrupt flags OR-ed together to set multiple interrupt sources.