AT32F421
Series Reference Manual
2022.11.11
Page 299
Rev 2.02
Bit 21: 20
HT
0x0
rw
Hour tens
Bit 19: 16
HU
0x0
rw
Hour units
Bit 15
Reserved
0x0
resd
Kept at its default value.
Bit 14: 12
MT
0x0
rw
Minute tens
Bit 11: 8
MU
0x0
rw
Minute units
Bit 7
Reserved
0x0
resd
Kept at its default value.
Bit 6: 4
ST
0x0
rw
Second tens
Bit 3: 0
SU
0x0
rw
Second units
17.4.2 ERTC date register (ERTC_DATE)
Bit
Register
Reset value
Type
Description
Bit 31: 24 Reserved
0x00
resd
Kept at its default value.
Bit 23: 20 YT
0x0
rw
Year tens
Bit 19: 16 YU
0x0
rw
Year units
Bit 15: 13 WK
0x1
rw
Week day
0: Forbidden
1: Monday
2: Tuesday
3: Wednesday
4: Thursday
5: Friday
6: Saturday
7: Sunday
Bit 12
MT
0x0
rw
Month tens
Bit 11: 8
MU
0x1
rw
Month units
Bit 7: 6
Reserved
0x0
resd
Kept at its default value.
Bit 5: 4
DT
0x0
rw
Date tens
Bit 3: 0
DU
0x1
rw
Date units
17.4.3 ERTC control register (ERTC_CTRL)
Bit
Register
Reset value
Type
Description
Bit 31: 24 Reserved
0x00
resd
Kept at its default value.
Bit 23
CALOEN
0x0
rw
Calibration output enable
0: Calibration output disabled
1: Calibration output enabled
Bit 22: 21 OUTSEL
0x0
rw
Output source selection
00: Output source disabled
01: Alarm clock A
10: Alarm clock B
11: Wakeup events
Bit 20
OUTP
0x0
rw
Output polarity
0: High
1: Low
Bit 19
CALOSEL
0x0
rw
Calibration output selection
0: 512Hz
1: 1Hz
Bit 18
BPR
0x0
rw
Battery powered domain data register
This bit in the battery powered domain is not affected by a
system reset. It is used to store the daylight saving time
change or others that need to be saved permanently.
Bit 17
DEC1H
0x0
wo
Decrease 1 hour
0: No effect
1: Subtract 1 hour
Note: This bit is applicable only when the current hour is
not 0. The next second takes effect when this bit is set
(don’t set this bit when the hour is being incremented)
Bit 16
ADD1H
0x0
wo
Add 1 hour