Rtc Alarm A Register (Rtc_Alrmar) - ST STM32WL5 Series Reference Manual

RM0453
Bits 31:0 SS[31:0]: Sub second value/Synchronous binary counter values
32.6.14

RTC alarm A register (RTC_ALRMAR)

This register can be written only when ALRAE is reset in RTC_CR register, or in initialization
mode.
Address offset: 0x40
Backup domain reset value: 0x0000 0000
System reset: not affected
31 30 29
WDSE
MSK4 DT[1:0]
L
rw rw rw
15 14 13
MSK2 MNT[2:0]
rw rw rw
Bit 31 MSK4: Alarm A date mask
Bit 30 WDSEL: Week day selection
Bits 29:28 DT[1:0]: Date tens in BCD format
Bits 27:24 DU[3:0]: Date units or day in BCD format
Bit 23 MSK3: Alarm A hours mask
Bit 22 PM: AM/PM notation
Bits 21:20 HT[1:0]: Hour tens in BCD format
Bits 19:16 HU[3:0]: Hour units in BCD format
Bit 15 MSK2: Alarm A minutes mask
Bits 14:12 MNT[2:0]: Minute tens in BCD format
Bits 11:8 MNU[3:0]: Minute units in BCD format
SS[31:0] is the value of the synchronous prescaler counter when the timestamp event
occurred.
28 27 26 25
DU[3:0]
rw rw rw rw
12 11 10 9
MNU[3:0]
rw rw rw rw
0: Alarm A set if the date/day match
1: Date/day don't care in alarm A comparison
0: DU[3:0] represents the date units
1: DU[3:0] represents the week day. DT[1:0] is don't care.
0: Alarm A set if the hours match
1: Hours don't care in alarm A comparison
0: AM or 24-hour format
1: PM
0: Alarm A set if the minutes match
1: Minutes don't care in alarm A comparison
24 23 22
MSK3 PM
rw rw rw
8 7 6
MSK1 ST[2:0]
rw rw rw
RM0453 Rev 1
Real-time clock (RTC)
21 20 19 18
HT[1:0] HU[3:0]
rw rw rw rw
5 4 3 2
SU[3:0]
rw rw rw rw
17 16
rw rw
1 0
rw rw
1031/1461
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