User Manual

Apollo3 Blue Datasheet
DS-A3-0p9p1 Page 550 of 909 2019 Ambiq Micro, Inc.
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12.4.2 RTC Registers
12.4.2.1 CTRLOW Register
RTC Counters Lower
OFFSET: 0x00000040
INSTANCE 0 ADDRESS: 0x40004240
This counter contains the values for hour, minutes, seconds and 100ths of a second Counter.
12.4.2.2 CTRUP Register
RTC Counters Upper
OFFSET: 0x00000044
INSTANCE 0 ADDRESS: 0x40004244
This register contains the day, month and year information. It contains which day in the week, and the
century as well. The information of the century can also be derived from the year information. The 31st bit
contains the error bit. See description in the register bit for condition when error is triggered.
Table 798: CTRLOW 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
CTRHR
RSVD
CTRMIN
RSVD
CTRSEC CTR100
Table 799: CTRLOW Register Bits
Bit Name Reset RW Description
31:30 RSVD 0x0 RO
RESERVED
29:24 CTRHR 0x1 RW
Hours Counter
23 RSVD 0x0 RO
RESERVED
22:16 CTRMIN 0x0 RW
Minutes Counter
15 RSVD 0x0 RO
RESERVED
14:8 CTRSEC 0x0 RW
Seconds Counter
7:0 CTR100 0x0 RW
100ths of a second Counter