User Manual

Apollo3 Blue Datasheet
DS-A3-0p9p1 Page 553 of 909 2019 Ambiq Micro, Inc.
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12.4.2.5 RTCCTL Register
RTC Control Register
OFFSET: 0x00000050
INSTANCE 0 ADDRESS: 0x40004250
This is the register control for the RTC module. It sets the 12 or 24 hours mode, enables counter writes
and sets the alarm repeat interval.
Table 805: ALMUP Register Bits
Bit Name Reset RW Description
31:19 RSVD 0x0 RO
RESERVED
18:16 ALMWKDY 0x0 RW
Weekdays Alarm
15:13 RSVD 0x0 RO
RESERVED
12:8 ALMMO 0x0 RW
Months Alarm
7:6 RSVD 0x0 RO
RESERVED
5:0 ALMDATE 0x0 RW
Date Alarm
Table 806: RTCCTL Register
3
1
3
0
2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
1
9
1
8
1
7
1
6
1
5
1
4
1
3
1
2
1
1
1
0
0
9
0
8
0
7
0
6
0
5
0
4
0
3
0
2
0
1
0
0
RSVD
HR1224
RSTOP
RPT
WRTC
Table 807: RTCCTL Register Bits
Bit Name Reset RW Description
31:6 RSVD 0x0 RO
RESERVED
5 HR1224 0x0 RW
Hours Counter mode
24HR = 0x0 - Hours in 24 hour mode
12HR = 0x1 - Hours in 12 hour mode
4RSTOP 0x0RW
RTC input clock control
RUN = 0x0 - Allow the RTC input clock to run
STOP = 0x1 - Stop the RTC input clock