Functions
void	Cy_SysClk_ExtRefSetFrequency (uint32_t freq)
	Sets the signal frequency of the External PLL Reference Clock Source (EXTREF) into the internal storage to be used in Cy_SysClk_PllGetFrequency. More...

uint32_t	Cy_SysClk_ExtRefGetFrequency (void)
	Returns the frequency of the External PLL Reference Source (EXT_REF) from the internal storage. More...

Detailed Description

Function Documentation

void Cy_SysClk_ExtRefSetFrequency ( uint32_t freq )

Sets the signal frequency of the External PLL Reference Clock Source (EXTREF) into the internal storage to be used in Cy_SysClk_PllGetFrequency.

Parameters

freq	The frequency of the External PLL Reference Source. Valid range is 1000000...48000000 (1...48 MHz) and also 0. Zero means the external clock signal is not applied.

Function Usage: /* Scenario: External precision 4MHz reference clock is needed for PLL. */
/* Configure the pin P0_6 to be an external reference input */
Cy_GPIO_Pin_FastInit(GPIO_PRT0, 6UL, CY_GPIO_DM_HIGHZ, 0UL, P0_6_EXCO_PLL_REF_IN);
/* Set the EXTREF frequency to 4MHz */
Cy_SysClk_ExtRefSetFrequency(4000000UL);
/* Set the EXTREF as the source for PLL */
if (CY_SYSCLK_SUCCESS != Cy_SysClk_PllSetSource(0UL, CY_SYSCLK_PLL_SRC_EXTREF))
{
/* Insert error handling */
}
/* In case if there is a need to get the EXTREF frequency */
uint32_t extRefFrequency = Cy_SysClk_ExtRefGetFrequency();

uint32_t Cy_SysClk_ExtRefGetFrequency ( void )

Returns the frequency of the External PLL Reference Source (EXT_REF) from the internal storage.

Function Usage: /* Scenario: External precision 4MHz reference clock is needed for PLL. */
/* Configure the pin P0_6 to be an external reference input */
Cy_GPIO_Pin_FastInit(GPIO_PRT0, 6UL, CY_GPIO_DM_HIGHZ, 0UL, P0_6_EXCO_PLL_REF_IN);
/* Set the EXTREF frequency to 4MHz */
Cy_SysClk_ExtRefSetFrequency(4000000UL);
/* Set the EXTREF as the source for PLL */
if (CY_SYSCLK_SUCCESS != Cy_SysClk_PllSetSource(0UL, CY_SYSCLK_PLL_SRC_EXTREF))
{
/* Insert error handling */
}
/* In case if there is a need to get the EXTREF frequency */
uint32_t extRefFrequency = Cy_SysClk_ExtRefGetFrequency();