Functions

General Description

Functions
void	Cy_SysClk_LpEcoConfigure (cy_en_clkbak_lpeco_loadcap_range_t capValue, cy_en_clkbak_lpeco_frequency_range_t freqValue, cy_en_clkbak_lpeco_max_amplitude_t ampValue, bool ampDetEn)
	Configures the low-power external crystal oscillator based on crystal characteristics. More...
cy_en_sysclk_status_t	Cy_SysClk_LpEcoEnable (uint32_t timeoutus)
	Enables the low-power external crystal oscillator (LPECO). More...
void	Cy_SysClk_LpEcoDisable (void)
	Disables the low-power external crystal oscillator (LPECO). More...
void	Cy_SysClk_LpEcoSetFrequency (uint32_t freq)
	Stores the low-power external crystal oscillator (LPECO) frequency in a global variable within Sysclk driver. More...
uint32_t	Cy_SysClk_LpEcoGetFrequency (void)
	Returns the frequency of the low-power external crystal oscillator (LPECO). More...
cy_en_sysclk_status_t	Cy_SysClk_LpEcoPrescaleConfigure (bool enable, uint32_t int_div, uint32_t frac_div)
	Configures the low-power external crystal oscillator (LPECO) Prescaler and derives clk_lpeco_prescaler. More...
bool	Cy_SysClk_LpEcoPrescaleIsEnabled (void)
	Reports whether or not LPECO Prescale is enabled. More...
bool	Cy_SysClk_LpEcoAmplitudeOkay (void)
	Reports the current status of the low-power external crystal oscillator (LPECO) amplitude detection. More...
bool	Cy_SysClk_LpEcoIsReady (void)
	Indicates whether or not the low-power external crystal oscillator (LPECO) has had enough time to start. More...

Function Documentation

Cy_SysClk_LpEcoConfigure()

void Cy_SysClk_LpEcoConfigure	(	cy_en_clkbak_lpeco_loadcap_range_t	capValue,
		cy_en_clkbak_lpeco_frequency_range_t	freqValue,
		cy_en_clkbak_lpeco_max_amplitude_t	ampValue,
		bool	ampDetEn
	)

Configures the low-power external crystal oscillator based on crystal characteristics.

Parameters

capValue	cy_en_clkbak_lpeco_loadcap_range_t
freqValue	cy_en_clkbak_lpeco_frequency_range_t
ampValue	cy_en_clkbak_lpeco_max_amplitude_t
ampDetEn	Enable amplitude detection always (true) or only on init (false)

Note

This API is available for TVIIC devices.

Function Usage

    /* Scenario: LPECO needs to be configured. The LPECO pins are configured
                 using the gpio driver (SRSS_LPECO_IN_PIN, SRSS_LPECO_OUT_PIN).
                 The LPECO crystal has the following characteristics:
                   Frequency: 8.00 MHz
                   Load capacitance: 18 pF */

    /* Disable the LPECO before configuring */
    Cy_SysClk_LpEcoDisable();

    /* Configure the LPECO with its characteristics */
    if(CY_SYSCLK_SUCCESS != Cy_SysClk_EcoConfigure(CY_SYSCLK_BAK_LPECO_LCAP_15TO20PF,
                                                   CY_SYSCLK_BAK_LPECO_FREQ_6TO8MHZ,
                                                   CY_SYSCLK_BAK_LPECO_AMP_MAX_1P35V,
                                                   true))
    {
        /* Insert error handling */
    }

    /* Enable the LPECO with a timeout of 3000 microseconds */
    if(CY_SYSCLK_SUCCESS != Cy_SysClk_LpEcoEnable(3000UL))
    {
        /* Insert error handling */
    }

Cy_SysClk_LpEcoEnable()

cy_en_sysclk_status_t Cy_SysClk_LpEcoEnable

(

uint32_t

timeoutus

)

Enables the low-power external crystal oscillator (LPECO).

This function should be called after Cy_SysClk_LpEcoConfigure.

Parameters

timeoutus

Amount of time in microseconds to wait for the LPECO to stabilize. To avoid waiting for stabilization, set this parameter to 0.

Returns

Error / status code:
CY_SYSCLK_SUCCESS - ECO locked
CY_SYSCLK_TIMEOUT - ECO timed out and did not lock
CY_SYSCLK_INVALID_STATE - ECO already enabled

Note

Call SystemCoreClockUpdate after this function calling if it affects the CLK_HF0 or CLK_HF1 frequency.

This API is available for TVIIC devices.

Function Usage

    /* Scenario: LPECO is successfully configured and needs to be enabled. The
                 LPECO pins are configured using the gpio driver
                 (SRSS_LPECO_IN_PIN, SRSS_LPECO_OUT_PIN). */

    uint32_t lpecofreq = 0UL; /* Variable to store the LPECO frequency */

    /* Enable the LPECO with a timeout of 5000 microseconds */
    if(CY_SYSCLK_SUCCESS == Cy_SysClk_LpEcoEnable(5000UL))
    {
        lpecofreq = Cy_SysClk_LpEcoGetFrequency();
        /* Now lpecofreq contains an actual LPECO frequency */
    }
    else
    {
        /* Insert error handling */
    }

    /* Set the path muxes and configure the downstream clocks. For example,
       the LPECO can source the FLL through path 0 clock or it can source the
       PLL through path 1 clock. */

Cy_SysClk_LpEcoDisable()

void Cy_SysClk_LpEcoDisable

(

void

)

Disables the low-power external crystal oscillator (LPECO).

This function should not be called if the LPECO is sourcing clkHf[0] or clkHf[1].

Note

This API is available for TVIIC devices.

Function Usage

    /* Scenario: LPECO sources path 2 clock, which sources HFCLK2. The LPECO
                 needs to be disabled and replaced with the IMO for HFCLK2. */

    /* Update the path 2 clock to IMO */
    (void)Cy_SysClk_ClkPathSetSource(2UL, CY_SYSCLK_CLKPATH_IN_IMO);

    /* Disable the LPECO */
    Cy_SysClk_LpEcoDisable();

Cy_SysClk_LpEcoSetFrequency()

void Cy_SysClk_LpEcoSetFrequency

(

uint32_t

freq

)

Stores the low-power external crystal oscillator (LPECO) frequency in a global variable within Sysclk driver.

Parameters

freq	Operating frequency of the crystal in Hz. Valid range: 3990000...8010000 (3.99..8.01 MHz).

Note

This API is available for TVIIC devices.

Cy_SysClk_LpEcoGetFrequency()

uint32_t Cy_SysClk_LpEcoGetFrequency

(

void

)

Returns the frequency of the low-power external crystal oscillator (LPECO).

Returns

The frequency of the LPECO in Hz.

Note

If the LPECO is not enabled or stable - a zero is returned.

This API is available for TVIIC devices.

Cy_SysClk_LpEcoPrescaleConfigure()

cy_en_sysclk_status_t Cy_SysClk_LpEcoPrescaleConfigure	(	bool	enable,
		uint32_t	int_div,
		uint32_t	frac_div
	)

Configures the low-power external crystal oscillator (LPECO) Prescaler and derives clk_lpeco_prescaler.

Parameters

enable	LPECO Prescaler enable/disable.
int_div	10-bit integer value. Subtract one from the desired divide value when using this parameter. For example , to divide by 1, int_div should be set to 0.
frac_div	8-bit fraction value.

Returns

Error / status code:
CY_SYSCLK_SUCCESS - LPECO prescaler configuration completed successfully
CY_SYSCLK_BAD_PARAM - One or more invalid parameters
CY_SYSCLK_INVALID_STATE - LPECO already enabled

Note

This API is available for TVIIC devices.

Function Usage

    /* Scenario: LPECO is successfully enabled and the LPECO prescaler needs
                 to be configured to run the RTC. The LPECO is running at
                 8.00 MHz and needs to be divided down to 32.768 kHz. */

    /* divider value = 8000000 / 32768 = 244.140625 */
    /* int_div = 244 - 1 = 243 */
    /* frac_div = 256 * 0.140625 = 36 */
    if(CY_SYSCLK_SUCCESS != Cy_SysClk_LpEcoPrescaleConfigure(true, 243, 36))
    {
        /* Insert error handling */
    }

Cy_SysClk_LpEcoPrescaleIsEnabled()

bool Cy_SysClk_LpEcoPrescaleIsEnabled

(

void

)

Reports whether or not LPECO Prescale is enabled.

Returns

false = disabled
true = enabled

Note

This API is available for TVIIC devices.

Cy_SysClk_LpEcoAmplitudeOkay()

bool Cy_SysClk_LpEcoAmplitudeOkay

(

void

)

Reports the current status of the low-power external crystal oscillator (LPECO) amplitude detection.

Returns

false = Insufficient oscillation amplitude OR the amplitude detector is off
true = Sufficient oscillation amplitude is detected

Note

This API is available for TVIIC devices.

Function Usage

    /* Scenario: Query the status of the LPECO amplitude detector and take
                 action based on the results. */

    if(Cy_SysClk_LpEcoAmplitudeOkay())
    {
        /* Oscillation amplitude is sufficient */
    }
    else
    {
        /* Oscillation amplitude is not sufficient OR amplitude detection is
        disabled */
    }

Cy_SysClk_LpEcoIsReady()

bool Cy_SysClk_LpEcoIsReady

(

void

)

Indicates whether or not the low-power external crystal oscillator (LPECO) has had enough time to start.

Returns

false = LPECO not stable
true = LPECO stable

Note

This API is available for TVIIC devices.

Function Usage

    /* Scenario: Query the LPECO status to see if it has started and take
                 action based on the results. */

    if(Cy_SysClk_LpEcoIsReady())
    {
        /* The LPECO has had enough time to start */
    }
    else
    {
        /* The LPECO has not started */
    }