Functions

General Description

Functions
void	Cy_SysClk_EcoSetFrequency (uint32_t freq)
	Stores the external crystal oscillator (ECO) frequency in a global variable within Sysclk driver. More...
cy_en_sysclk_status_t	Cy_SysClk_EcoManualConfigure (const cy_stc_clk_eco_config_t *ecoConfig)
	Configures the external crystal oscillator (ECO) trim bits based on crystal characteristics. More...
cy_en_sysclk_status_t	Cy_SysClk_EcoEnable (uint32_t timeoutus)
	Enables the external crystal oscillator (ECO). More...
uint32_t	Cy_SysClk_EcoGetFrequency (void)
	Returns the frequency of the external crystal oscillator (ECO). More...
void	Cy_SysClk_EcoDisable (void)
	Disables the external crystal oscillator (ECO). More...
uint32_t	Cy_SysClk_EcoGetStatus (void)
	Reports the current status of the external crystal oscillator (ECO). More...
cy_en_sysclk_status_t	Cy_SysClk_EcoPrescaleConfigure (uint32_t enable, uint32_t int_div, uint32_t frac_div)
	Configures the external crystal oscillator (ECO) using ECO Prescaler Configuration Register and derives clk_eco_prescaler. More...
bool	Cy_SysClk_EcoPrescaleIsEnabled (void)
	Reports whether or not ECO Prescale is enabled. More...
uint32_t	Cy_SysClk_EcoPrescaleGetFrequency (void)
	Returns the frequency of the external crystal oscillator (ECO) prescaler. More...

Function Documentation

Cy_SysClk_EcoSetFrequency()

void Cy_SysClk_EcoSetFrequency

(

uint32_t

freq

)

Stores the external crystal oscillator (ECO) frequency in a global variable within Sysclk driver.

Parameters

freq	Operating frequency of the crystal in Hz. Valid range: 16000000...35000000 (16..35 MHz).

Cy_SysClk_EcoManualConfigure()

cy_en_sysclk_status_t Cy_SysClk_EcoManualConfigure

(

const cy_stc_clk_eco_config_t *

ecoConfig

)

Configures the external crystal oscillator (ECO) trim bits based on crystal characteristics.

This function should be called only when the ECO is disabled.

Parameters

ecoConfig

cy_stc_clk_eco_config_t

Note

This API expects the trims to be calculated outside this API scope, so refer and use the ECO calculators excel sheet for the platform to obtain the trims.

This API is not Secure Aware. It uses the PPC regions SRSS_SECURE and SRSS_MAIN. The SRSS_SECURE region is always secured. Thus, this API is only safe to call if SRSS_MAIN is also configured as secure.

Returns

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

Cy_SysClk_EcoEnable()

cy_en_sysclk_status_t Cy_SysClk_EcoEnable

(

uint32_t

timeoutus

)

Enables the external crystal oscillator (ECO).

This function should be called after Cy_SysClk_EcoConfigure.

Parameters

timeoutus

Amount of time in microseconds to wait for the ECO 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
CY_SYSCLK_UNSUPPORTED_STATE - ECO is not present

Note

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

Take into account the possible platform specific clkHf (and further clocking chain links) frequency limitations while using this API.

Function Usage

    /* Scenario: ECO is successfully configured and needs to be enabled. The
                 ECO pins are configured using the gpio driver
                 (SRSS_ECO_IN_PIN, SRSS_ECO_OUT_PIN). */
 
    uint32_t ecofreq = 0UL; /* Variable to store the ECO frequency */
 
    /* Enable the ECO with a timeout of 1000 microseconds */
    if(CY_SYSCLK_SUCCESS == Cy_SysClk_EcoEnable(1000UL))
    {
        ecofreq = Cy_SysClk_EcoGetFrequency();
        /* Now ecofreq contains an actual ECO frequency */
    }
    else
    {
        /* Insert error handling */
    }
 
    /* Set the path muxes and configure the downstream clocks. For example,
       the ECO can source the FLL through path 0 clock or it can source the PLL
       through path 1 clock. */

Cy_SysClk_EcoGetFrequency()

uint32_t Cy_SysClk_EcoGetFrequency

(

void

)

Returns the frequency of the external crystal oscillator (ECO).

Returns

The frequency of the ECO.

Note

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

Function Usage

    /* Scenario: ECO is successfully configured and needs to be enabled. The
                 ECO pins are configured using the gpio driver
                 (SRSS_ECO_IN_PIN, SRSS_ECO_OUT_PIN). */
 
    uint32_t ecofreq = 0UL; /* Variable to store the ECO frequency */
 
    /* Enable the ECO with a timeout of 1000 microseconds */
    if(CY_SYSCLK_SUCCESS == Cy_SysClk_EcoEnable(1000UL))
    {
        ecofreq = Cy_SysClk_EcoGetFrequency();
        /* Now ecofreq contains an actual ECO frequency */
    }
    else
    {
        /* Insert error handling */
    }
 
    /* Set the path muxes and configure the downstream clocks. For example,
       the ECO can source the FLL through path 0 clock or it can source the PLL
       through path 1 clock. */

Cy_SysClk_EcoDisable()

void Cy_SysClk_EcoDisable

(

void

)

Disables the external crystal oscillator (ECO).

This function should not be called if the ECO is sourcing clkHf[0].

Function Usage

    /* Scenario: ECO sources path 2 clock, which sources HFCLK2. The ECO 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 ECO */
    Cy_SysClk_EcoDisable();

Cy_SysClk_EcoGetStatus()

uint32_t Cy_SysClk_EcoGetStatus

(

void

)

Reports the current status of the external crystal oscillator (ECO).

Returns

CY_SYSCLK_ECOSTAT_UNUSABLE = ECO does not have sufficient amplitude
CY_SYSCLK_ECOSTAT_OK = ECO has sufficient amplitude but may not be meeting accuracy and duty cycle specifications
CY_SYSCLK_ECOSTAT_READY = ECO has sufficient time to stabilize it's power
CY_SYSCLK_ECOSTAT_OK_AND_READY = ECO has fully stabilized

Function Usage

    /* Scenario: Query the status of the ECO */
 
    uint32_t ecoStatus = Cy_SysClk_EcoGetStatus();
 
    /* Perform action based on the ECO status */
    switch(ecoStatus)
    {
        case CY_SYSCLK_ECOSTAT_UNUSABLE:
            /* Amplitude is not sufficient. Try waiting longer before
               attempting to reconfigure the ECO */
        break;
        case CY_SYSCLK_ECOSTAT_OK:
            /* Amplitude is correct but the ECO is not yet stable. Try
               waiting longer before attempting to reconfigure the ECO */
        break;
        case CY_SYSCLK_ECOSTAT_READY:
            /* Power is correct and stable */
        break;
        case CY_SYSCLK_ECOSTAT_OK_AND_READY:
            /* ECO is stable and ready for use */
        break;
        default:
            /* Invalid state. Perform error handling. */
        break;
    }

Cy_SysClk_EcoPrescaleConfigure()

cy_en_sysclk_status_t Cy_SysClk_EcoPrescaleConfigure	(	uint32_t	enable,
		uint32_t	int_div,
		uint32_t	frac_div
	)

Configures the external crystal oscillator (ECO) using ECO Prescaler Configuration Register and derives clk_eco_prescaler.

Parameters

enable	ECO Prescaler enable/disable.
int_div	10-bit integer value.
frac_div	8-bit fraction value.

Returns

Error / status code:
CY_SYSCLK_SUCCESS - ECO configuration completed successfully
CY_SYSCLK_BAD_PARAM - One or more invalid parameters
CY_SYSCLK_INVALID_STATE - ECO already enabled
CY_SYSCLK_UNSUPPORTED_STATE - ECO is not present

Cy_SysClk_EcoPrescaleIsEnabled()

bool Cy_SysClk_EcoPrescaleIsEnabled

(

void

)

Reports whether or not ECO Prescale is enabled.

Returns

false = disabled
true = enabled

Cy_SysClk_EcoPrescaleGetFrequency()

uint32_t Cy_SysClk_EcoPrescaleGetFrequency

(

void

)

Returns the frequency of the external crystal oscillator (ECO) prescaler.

Returns

The frequency of the ECO Prescaler.

Note

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