User Manual
Apollo3 Blue Datasheet
DS-A3-0p9p1 Page 534 of 909 2019 Ambiq Micro, Inc.
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12.2.2.5 CLKOUT Register
CLKOUT Frequency Select
OFFSET: 0x00000010
INSTANCE 0 ADDRESS: 0x40004010
This register enables the CLKOUT to the GPIOs, and selects the clock source to that.
5:2 RSVD 0x0 RO
RESERVED
1STOPRC 0x0RW
Stop the LFRC Oscillator to the RTC
EN = 0x0 - Enable the LFRC Oscillator to drive the RTC
STOP = 0x1 - Stop the LFRC Oscillator when driving the RTC
0 STOPXT 0x0 RW
Stop the XT Oscillator to the RTC
EN = 0x0 - Enable the XT Oscillator to drive the RTC
STOP = 0x1 - Stop the XT Oscillator when driving the RTC
Table 768: CLKOUT 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
CKEN
RSVD
CKSEL
Table 769: CLKOUT Register Bits
Bit Name Reset RW Description
31:8 RSVD 0x0 RO
RESERVED
7 CKEN 0x0 RW
Enable the CLKOUT signal
DIS = 0x0 - Disable CLKOUT
EN = 0x1 - Enable CLKOUT
6 RSVD 0x0 RO
RESERVED
Table 767: OCTRL Register Bits
Bit Name Reset RW Description