Functions

Functions
cy_en_sysclk_status_t	Cy_SysClk_ClkHfSetSource (cy_en_sysclk_clkhf_src_t source)
	Selects the source of the HFCLK. More...
cy_en_sysclk_clkhf_src_t	Cy_SysClk_ClkHfGetSource (void)
	Reports the source of the HFCLK. More...
__STATIC_INLINE void	Cy_SysClk_ClkHfSetDivider (cy_en_sysclk_dividers_t divider)
	Sets a divider value for HFCLK. More...
__STATIC_INLINE cy_en_sysclk_dividers_t	Cy_SysClk_ClkHfGetDivider (void)
	Returns the HFCLK divider value. More...
uint32_t	Cy_SysClk_ClkHfGetFrequency (void)
	Reports the frequency of the HFCLK. More...

Detailed Description

Function Documentation

Cy_SysClk_ClkHfSetSource()

cy_en_sysclk_status_t Cy_SysClk_ClkHfSetSource

(

cy_en_sysclk_clkhf_src_t

source

)

Selects the source of the HFCLK.

Parameters

source

cy_en_sysclk_clkhf_src_t

Returns

Error / status code cy_en_sysclk_status_t :
CY_SYSCLK_SUCCESS - the source is successfully set;
CY_SYSCLK_INVALID_STATE - the selected clock source is not enabled or does not working;
CY_SYSCLK_BAD_PARAM - the source parameter is invalid.

Note

Call SystemCoreClockUpdate after this function calling if SYSCLK frequency is affected.

Call Cy_SysLib_SetWaitStates before this function calling if SYSCLK frequency is increasing.

Call Cy_SysLib_SetWaitStates after this function calling if SYSCLK frequency is decreasing.

Function Usage

    /* Scenario: HFCLK needs to be switched to the ECO (if ECO is enabled, of course) */
    if (Cy_SysClk_EcoIsEnabled() && (CY_SYSCLK_ECO_STABLE == Cy_SysClk_EcoGetStatus())) /* If ECO enabled and stabilized */
    {
        if (CY_SYSCLK_PLL_BYP_ECO != Cy_SysClk_PllGetBypassState(0U))
        {
            Cy_SysClk_PllBypass(0U, CY_SYSCLK_PLL_BYP_ECO); /* First make multiplexing inside the EXCO block */
        }

        sysclkStatus = Cy_SysClk_ClkHfSetSource(CY_SYSCLK_CLKHF_IN_EXCO);

        if (CY_SYSCLK_SUCCESS != sysclkStatus)
        {
            /* Insert error handling */
        }
    }

    /* Scenario: HFCLK needs to be switched to the HPOSC (if HPOSC is enabled, of course) */
    if (Cy_SysClk_HposcIsEnabled()) /* If HPOSC enabled */
    {

        sysclkStatus = Cy_SysClk_ClkHfSetSource(CY_SYSCLK_CLKHF_IN_HPOSC);

        if (CY_SYSCLK_SUCCESS != sysclkStatus)
        {
            /* Insert error handling */
        }
    }

Cy_SysClk_ClkHfGetSource()

cy_en_sysclk_clkhf_src_t Cy_SysClk_ClkHfGetSource

(

void

)

Reports the source of the HFCLK.

Returns

cy_en_sysclk_clkhf_src_t :
CY_SYSCLK_CLKHF_IN_IMO - IMO - Internal R/C Oscillator.
CY_SYSCLK_CLKHF_IN_EXTCLK - EXTCLK - External Clock Pin.
CY_SYSCLK_CLKHF_IN_EXCO - EXCO block output, ECO or PLL, use Cy_SysClk_PllBypass to select between them. CY_SYSCLK_CLKHF_IN_HPOSC - High Precision Oscillator.

Function Usage

    /* Scenario: If ECO is enabled and sources HFCLK then the ECO needs
     * to be disabled and replaced with the IMO for HFCLK
     */

    if (Cy_SysClk_EcoIsEnabled()) /* If ECO enabled */
    {
        /* If ECO sources HFCLK */
        if ((CY_SYSCLK_CLKHF_IN_EXCO == Cy_SysClk_ClkHfGetSource()) &&
           ((CY_SYSCLK_PLL_BYP_ECO == Cy_SysClk_PllGetBypassState(0UL)) ||
            (CY_SYSCLK_PLL_SRC_ECO == Cy_SysClk_PllGetSource(0UL))))
        {
            /* First update the HFCLK clock to IMO */
            if (CY_SYSCLK_SUCCESS != Cy_SysClk_ClkHfSetSource(CY_SYSCLK_CLKHF_IN_IMO))
            {
                /* Insert error handling */
            }
        }

        /* Disable the ECO */
        Cy_SysClk_EcoDisable();
    }

Cy_SysClk_ClkHfSetDivider()

__STATIC_INLINE void Cy_SysClk_ClkHfSetDivider

(

cy_en_sysclk_dividers_t

divider

)

Sets a divider value for HFCLK.

Parameters

divider

cy_en_sysclk_dividers_t

Note

Also call Cy_SysClk_ClkHfSetSource to set the HFCLK source.

Call SystemCoreClockUpdate after this function calling.

Call Cy_SysLib_SetWaitStates before calling this function if SYSCLK frequency is increasing.

Call Cy_SysLib_SetWaitStates after calling this function if SYSCLK frequency is decreasing.

Function Usage

    /* Scenario: Set HFCLK divider to 8, to reduce frequency and save power */

    if(CY_SYSCLK_DIV_8 != Cy_SysClk_ClkHfGetDivider())
    {
        /* Set the HFCLK divider to 8 */
        (void)Cy_SysClk_ClkHfSetDivider(CY_SYSCLK_DIV_8);
    }

    /* Check the HFCLK frequency */
    uint32_t clkHfFreq = Cy_SysClk_ClkHfGetFrequency();

Cy_SysClk_ClkHfGetDivider()

__STATIC_INLINE cy_en_sysclk_dividers_t Cy_SysClk_ClkHfGetDivider

(

void

)

Returns the HFCLK divider value.

Returns

cy_en_sysclk_dividers_t :
CY_SYSCLK_NO_DIV - don't divide.
CY_SYSCLK_DIV_2 - divide by 2
CY_SYSCLK_DIV_4 - divide by 4
CY_SYSCLK_DIV_8 - divide by 8

Function Usage

    /* Scenario: Set HFCLK divider to 8, to reduce frequency and save power */

    if(CY_SYSCLK_DIV_8 != Cy_SysClk_ClkHfGetDivider())
    {
        /* Set the HFCLK divider to 8 */
        (void)Cy_SysClk_ClkHfSetDivider(CY_SYSCLK_DIV_8);
    }

    /* Check the HFCLK frequency */
    uint32_t clkHfFreq = Cy_SysClk_ClkHfGetFrequency();

Cy_SysClk_ClkHfGetFrequency()

uint32_t Cy_SysClk_ClkHfGetFrequency

(

void

)

Reports the frequency of the HFCLK.

Returns

The frequency, in Hz.

Note

The reported value may be zero, which indicates the frequency is unknown.

Function Usage

    /* Scenario: Set HFCLK divider to 8, to reduce frequency and save power */

    if(CY_SYSCLK_DIV_8 != Cy_SysClk_ClkHfGetDivider())
    {
        /* Set the HFCLK divider to 8 */
        (void)Cy_SysClk_ClkHfSetDivider(CY_SYSCLK_DIV_8);
    }

    /* Check the HFCLK frequency */
    uint32_t clkHfFreq = Cy_SysClk_ClkHfGetFrequency();