26.6.8 RTC Calendar Alarm Register

In UTC mode, this register view is not relevant, see RTC_CALALR (UTC_MODE).

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

To change one of the DATE, MONTH fields, it is recommended to disable the field before changing the value and then re-enable it after the change has been made. This requires up to three accesses to RTC_CALALR. The first access clears the enable corresponding to the field to change (DATEEN, MTHEN). If the field is already cleared, this access is not required. The second access performs the change of the value (DATE, MONTH). The third access is required to re-enable the field by writing 1 in DATEEN, MTHEN fields.

Name: RTC_CALALR
Offset: 0x14
Reset: 0x01010000
Property: Read/Write

Bit 3130292827262524 
 DATEEN DATE[5:0] 
Access R/WR/WR/WR/WR/WR/WR/W 
Reset 0000001 
Bit 2322212019181716 
 MTHEN  MONTH[4:0] 
Access R/WR/WR/WR/WR/WR/W 
Reset 000001 
Bit 15141312111098 
          
Access  
Reset  
Bit 76543210 
          
Access  
Reset  

Bit 31 – DATEEN Date Alarm Enable

ValueNameDescription
0 DISABLED

The date-matching alarm is disabled.

1 ENABLED

The date-matching alarm is enabled.

Bits 29:24 – DATE[5:0] Date Alarm

This field is the alarm field corresponding to the BCD-coded date counter.

Bit 23 – MTHEN Month Alarm Enable

ValueNameDescription
0 DISABLED

The month-matching alarm is disabled.

1 ENABLED

The month-matching alarm is enabled.

Bits 20:16 – MONTH[4:0] Month Alarm

This field is the alarm field corresponding to the BCD-coded month counter.