Kinetis SDK v.2.0 API Reference Manual  Rev. 0
Freescale Semiconductor, Inc.
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EWM: External Watchdog Monitor Driver

Overview

The KSDK provides a peripheral driver for the EWM module of Kinetis devices.

Typical use case

ewm_config_t config;
config.enableInterrupt = true;
config.compareLowValue = 0U;
config.compareHighValue = 0xAAU;
NVIC_EnableIRQ(WDOG_EWM_IRQn);
EWM_Init(base, &config);

Files

file  fsl_ewm.h
 

Data Structures

struct  ewm_config_t
 Describes ewm clock source. More...
 

Enumerations

enum  _ewm_interrupt_enable_t { kEWM_InterruptEnable = EWM_CTRL_INTEN_MASK }
 EWM interrupt configuration structure, default settings all disabled. More...
 
enum  _ewm_status_flags_t { kEWM_RunningFlag = EWM_CTRL_EWMEN_MASK }
 EWM status flags. More...
 

Driver version

#define FSL_EWM_DRIVER_VERSION   (MAKE_VERSION(2, 0, 1))
 EWM driver version 2.0.1. More...
 

EWM Initialization and De-initialization

void EWM_Init (EWM_Type *base, const ewm_config_t *config)
 Initializes the EWM peripheral. More...
 
void EWM_Deinit (EWM_Type *base)
 Deinitializes the EWM peripheral. More...
 
void EWM_GetDefaultConfig (ewm_config_t *config)
 Initializes the EWM configuration structure. More...
 

EWM functional Operation

static void EWM_EnableInterrupts (EWM_Type *base, uint32_t mask)
 Enables the EWM interrupt. More...
 
static void EWM_DisableInterrupts (EWM_Type *base, uint32_t mask)
 Disables the EWM interrupt. More...
 
static uint32_t EWM_GetStatusFlags (EWM_Type *base)
 Gets EWM all status flags. More...
 
void EWM_Refresh (EWM_Type *base)
 Service EWM. More...
 

Data Structure Documentation

struct ewm_config_t

Data structure for EWM configuration.

This structure is used to configure the EWM.

Data Fields

bool enableEwm
 Enable EWM module.
 
bool enableEwmInput
 Enable EWM_in input.
 
bool setInputAssertLogic
 EWM_in signal assertion state.
 
bool enableInterrupt
 Enable EWM interrupt.
 
uint8_t compareLowValue
 Compare low register value.
 
uint8_t compareHighValue
 Compare high register value.
 

Macro Definition Documentation

#define FSL_EWM_DRIVER_VERSION   (MAKE_VERSION(2, 0, 1))

Enumeration Type Documentation

This structure contains the settings for all of the EWM interrupt configurations.

Enumerator
kEWM_InterruptEnable 

Enable EWM to generate an interrupt.

This structure contains the constants for the EWM status flags for use in the EWM functions.

Enumerator
kEWM_RunningFlag 

Running flag, set when ewm is enabled.

Function Documentation

void EWM_Init ( EWM_Type *  base,
const ewm_config_t config 
)

This function is used to initialize the EWM. After calling, the EWM runs immediately according to the configuration. Note that except for interrupt enable control bit, other control bits and registers are write once after a CPU reset. Modifying them more than once generates a bus transfer error.

Example:

ewm_config_t config;
config.compareHighValue = 0xAAU;
EWM_Init(ewm_base,&config);
Parameters
baseEWM peripheral base address
configThe configuration of EWM
void EWM_Deinit ( EWM_Type *  base)

This function is used to shut down the EWM.

Parameters
baseEWM peripheral base address
void EWM_GetDefaultConfig ( ewm_config_t config)

This function initializes the EWM configure structure to default values. The default values are:

ewmConfig->enableEwm = true;
ewmConfig->enableEwmInput = false;
ewmConfig->setInputAssertLogic = false;
ewmConfig->enableInterrupt = false;
ewmConfig->ewm_lpo_clock_source_t = kEWM_LpoClockSource0;
ewmConfig->prescaler = 0;
ewmConfig->compareLowValue = 0;
ewmConfig->compareHighValue = 0xFEU;
Parameters
configPointer to EWM configuration structure.
See Also
ewm_config_t
static void EWM_EnableInterrupts ( EWM_Type *  base,
uint32_t  mask 
)
inlinestatic

This function enables the EWM interrupt.

Parameters
baseEWM peripheral base address
maskThe interrupts to enable The parameter can be combination of the following source if defined:
  • kEWM_InterruptEnable
static void EWM_DisableInterrupts ( EWM_Type *  base,
uint32_t  mask 
)
inlinestatic

This function enables the EWM interrupt.

Parameters
baseEWM peripheral base address
maskThe interrupts to disable The parameter can be combination of the following source if defined:
  • kEWM_InterruptEnable
static uint32_t EWM_GetStatusFlags ( EWM_Type *  base)
inlinestatic

This function gets all status flags.

Example for getting Running Flag:

uint32_t status;
status = EWM_GetStatusFlags(ewm_base) & kEWM_RunningFlag;
Parameters
baseEWM peripheral base address
Returns
State of the status flag: asserted (true) or not-asserted (false).
See Also
_ewm_status_flags_t
  • true: related status flag has been set.
  • false: related status flag is not set.
void EWM_Refresh ( EWM_Type *  base)

This function reset EWM counter to zero.

Parameters
baseEWM peripheral base address