26.6.1 RTC Control Register

This register can only be written if the WPEN bit is cleared in the System Controller Write Protection Mode register (SYSC_WPMR).

Name: RTC_CR
Offset: 0x00
Reset: 0x00000000
Property: Read/Write

Bit 3130292827262524 
          
Access  
Reset  
Bit 2322212019181716 
       CALEVSEL[1:0] 
Access R/WR/W 
Reset 00 
Bit 15141312111098 
       TIMEVSEL[1:0] 
Access R/WR/W 
Reset 00 
Bit 76543210 
       UPDCALUPDTIM 
Access R/WR/W 
Reset 00 

Bits 17:16 – CALEVSEL[1:0] Calendar Event Selection

The event that generates the flag CALEV in RTC_SR depends on the value of CALEVSEL

In UTC mode, this field has no effect on RTC_SR.

ValueNameDescription
0 WEEK Week change (every Monday at time 00:00:00)
1 MONTH Month change (every 01 of each month at time 00:00:00)
2 YEAR Year change (every January 1 at time 00:00:00)
3 YEAR Reserved

Bits 9:8 – TIMEVSEL[1:0] Time Event Selection

The event that generates the flag TIMEV in RTC_SR depends on the value of TIMEVSEL.

In UTC mode, this field has no effect on RTC_SR.

ValueNameDescription
0 MINUTE Minute change
1 HOUR Hour change
2 MIDNIGHT Every day at midnight
3 NOON Every day at noon

Bit 1 – UPDCAL Update Request Calendar Register

Calendar counting consists of day, date, month, year and century counters. Calendar counters can be programmed once this bit is set and acknowledged by the RTC_SR.ACKUPD bit.

In UTC mode, both UPDTIM and UPDCAL must be set to '1' in order to update the UTC time value.

ValueNameDescription
0 CLOSE_UPDATE No effect or, if UPDCAL has been previously written to 1, stops the update procedure.
1 START_UPDATE Stops the RTC calendar counting.

Bit 0 – UPDTIM Update Request Time Register

Time counting consists of second, minute and hour counters. Time counters can be programmed once this bit is set and acknowledged by the RTC_SR.ACKUPD bit.

In UTC mode, both UPDTIM and UPDCAL must be set to '1' in order to update the UTC time value.

ValueNameDescription
0 CLOSE_UPDATE No effect or, if UPDTIM has been previously written to 1, stops the update procedure.
1 START_UPDATE Stops the RTC time counting.