Real-time clock (RTC)
RM0090
816/1731
DocID018909 Rev 11
Note:
This register can be written only when ALRAWF is set to 1 in RTC_ISR, or in initialization
mode.
This register is write protected. The write access procedure is described in
26.6.9
RTC alarm B register (RTC_ALRMBR)
Address offset: 0x20
Backup domain reset value: 0x0000 0000
System reset: not affected
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
MSK4
WDSEL
DT[1:0]
DU[3:0]
MSK3
PM
HT[1:0]
HU[3:0]
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
MSK2
MNT[2:0]
MNU[3:0]
MSK1
ST[2:0]
SU[3:0]
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
Bit 31
MSK4
: Alarm B date mask
0: Alarm B set if the date and day match
1: Date and day don’t care in Alarm B comparison
Bit 30
WDSEL
: Week day selection
0: DU[3:0] represents the date units
1: DU[3:0] represents the week day. DT[1:0] is don’t care.
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 B hours mask
0: Alarm B set if the hours match
1: Hours don’t care in Alarm B comparison
Bit 22
PM:
AM/PM notation
0: AM or 24-hour format
1: PM
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 B minutes mask
0: Alarm B set if the minutes match
1: Minutes don’t care in Alarm B comparison
Bits 14:12
MNT[2:0]
: Minute tens in BCD format
Bits 11:8
MNU[3:0]
: Minute units in BCD format
Bit 7
MSK1
: Alarm B seconds mask
0: Alarm B set if the seconds match
1: Seconds don’t care in Alarm B comparison
Bits 6:4
ST[2:0]
: Second tens in BCD format
Bits 3:0
SU[3:0]
: Second units in BCD format