General

General Description

Functions
cy_en_rtc_status_t	Cy_RTC_Init (cy_stc_rtc_config_t const *config)
	Initializes the RTC driver. More...
cy_en_rtc_status_t	Cy_RTC_SetDateAndTime (cy_stc_rtc_config_t const *dateTime)
	Sets the time and date values into the RTC_TIME and RTC_DATE registers. More...
void	Cy_RTC_GetDateAndTime (cy_stc_rtc_config_t *dateTime)
	Gets the current RTC time and date. More...
cy_en_rtc_status_t	Cy_RTC_SetDateAndTimeDirect (uint32_t sec, uint32_t min, uint32_t hour, uint32_t date, uint32_t month, uint32_t year)
	Sets the time and date values into the RTC_TIME and RTC_DATE registers using direct time parameters. More...
cy_en_rtc_status_t	Cy_RTC_SetHoursFormat (cy_en_rtc_hours_format_t hoursFormat)
	Sets the 12/24-hour mode. More...
void	Cy_RTC_SelectFrequencyPrescaler (cy_en_rtc_clock_freq_t clkSel)
	Selects the RTC pre-scaler value and changes its clock frequency. More...

Function Documentation

Cy_RTC_Init()

cy_en_rtc_status_t Cy_RTC_Init

(

cy_stc_rtc_config_t const *

config

)

Initializes the RTC driver.

Parameters

*config

The pointer to the RTC configuration structure, see cy_stc_rtc_config_t.

Returns

Checking result. If the pointer is NULL, returns an error. See cy_en_rtc_status_t.

Cy_RTC_SetDateAndTime()

cy_en_rtc_status_t Cy_RTC_SetDateAndTime

(

cy_stc_rtc_config_t const *

dateTime

)

Sets the time and date values into the RTC_TIME and RTC_DATE registers.

Parameters

dateTime

The pointer to the RTC configuration structure, see cy_stc_rtc_config_t.

Returns

A validation check result of date and month. Returns an error, if the date range is invalid. See cy_en_rtc_status_t.

Cy_RTC_GetDateAndTime()

void Cy_RTC_GetDateAndTime

(

cy_stc_rtc_config_t *

dateTime

)

Gets the current RTC time and date.

The AHB RTC Time and Date register values are stored into the *dateTime structure.

Parameters

dateTime

The RTC time and date structure. See Data Structures.

Cy_RTC_SetDateAndTimeDirect()

cy_en_rtc_status_t Cy_RTC_SetDateAndTimeDirect	(	uint32_t	sec,
		uint32_t	min,
		uint32_t	hour,
		uint32_t	date,
		uint32_t	month,
		uint32_t	year
	)

Sets the time and date values into the RTC_TIME and RTC_DATE registers using direct time parameters.

Parameters

sec	The second valid range is [0-59].
min	The minute valid range is [0-59].
hour	The hour valid range is [0-23]. This parameter should be presented in the 24-hour format.

The function reads the current 12/24-hour mode, then converts the hour value properly as the mode.

Parameters

date	The date valid range is [1-31], if the month of February is selected as the Month parameter, then the valid range is [0-29].
month	The month valid range is [1-12].
year	The year valid range is [0-99].

Returns

A validation check result of date and month. Returns an error, if the date range is invalid or the RTC time and date set was cancelled: the RTC Write bit was not set, the RTC was synchronizing. See cy_en_rtc_status_t.

Cy_RTC_SetHoursFormat()

cy_en_rtc_status_t Cy_RTC_SetHoursFormat

(

cy_en_rtc_hours_format_t

hoursFormat

)

Sets the 12/24-hour mode.

Parameters

hoursFormat

The current hour format, see cy_en_rtc_hours_format_t.

Returns

A validation check result of RTC register update. See cy_en_rtc_status_t.

Cy_RTC_SelectFrequencyPrescaler()

void Cy_RTC_SelectFrequencyPrescaler

(

cy_en_rtc_clock_freq_t

clkSel

)

Selects the RTC pre-scaler value and changes its clock frequency.

If the external 32.768 kHz WCO is absent on the board, the RTC can be driven by a 32.768kHz square clock source or an external 50-Hz or 60-Hz sine-wave clock source, for example the wall AC frequency.

Parameters

clkSel

clock frequency, see cy_en_rtc_clock_freq_t.

In addition to generating the 32.768 kHz clock from external crystals, the WCO can be sourced by an external clock source (50 Hz or 60Hz), even the wall AC frequency as a timebase. The API helps select between the RTC sources:

• A 32.768 kHz digital clock source.
• An external 50-Hz or 60-Hz sine-wave clock source.

If you want to use an external 50-Hz or 60-Hz sine-wave clock source to drive the RTC, the next procedure is required:

1. Disable the WCO
   
2. Bypass the WCO using the Cy_SysClk_WcoBypass() function.
3. Configure both wco_out and wco_in pins. Note that only one of the wco pins should be driven and the other wco pin should be floating, which depends on the source that drives the RTC (*1).
4. Call Cy_RTC_SelectFrequencyPrescaler(CY_RTC_FREQ_60_HZ), if you want to drive the WCO, for example, with a 60 Hz source.
5. Enable the WCO.

If you want to use the WCO after using an external 50-Hz or 60-Hz sine-wave clock source:

1. Disable the WCO.
2. Switch-off the WCO bypass using the Cy_SysClk_WcoBypass() function.
3. Drive off the wco pin with an external signal source.
4. Call Cy_RTC_SelectFrequencyPrescaler(CY_RTC_FREQ_WCO_32768_HZ).
5. Enable the WCO.

(1) - Refer to the device TRM to know how to configure the wco pins properly and which wco pin should be driven/floating.

Warning

There is a limitation to the external clock source frequencies. Only two frequencies are allowed - 50 Hz or 60 Hz. Note that this limitation is related to the RTC pre-scaling feature presented in this function. This limitation is not related to WCO external clock sources which can drive the WCO in Bypass mode.