Datasheet

PCF2129 All information provided in this document is subject to legal disclaimers. © NXP Semiconductors N.V. 2014. All rights reserved.
Product data sheet Rev. 7 — 19 December 2014 50 of 86
NXP Semiconductors
PCF2129
Accurate RTC with integrated quartz crystal for industrial applications
[1] F
0
is clocked at 32.768 kHz.
Table 73. First increment of time circuits after stop release
Bit
STOP
Prescaler bits
[1]
F
0
to F
8
- F
9
to F
14
1Hz tick Time
hh:mm:ss
Comment
Clock is running normally
0
010000111-010100 12:45:12 prescaler counting normally
STOP bit is activated by user. F
0
to F
8
are not reset and values cannot be predicted externally
1
xxxxxxxxx-000000 12:45:12 prescaler is reset; time circuits are frozen
New time is set by user
1
xxxxxxxxx-000000 08:00:00 prescaler is reset; time circuits are frozen
STOP bit is released by user
0
xxxxxxxxx-000000 08:00:00 prescaler is now running
0
xxxxxxxxx-100000 08:00:00
0
xxxxxxxxx-100000 08:00:00
0
xxxxxxxxx-110000 08:00:00
:: :
0
111111111-111110 08:00:00
0
000000000-000001 08:00:01 0 to 1 transition of F
14
increments the time circuits
0
100000000-000001 08:00:01
:: :
0
111111111-111111 08:00:01
0
000000000-000000 08:00:01
0
100000000-000000
:: :
0
111111111-111110 08:00:01
0
000000000-000001 08:00:02 0 to 1 transition of F
14
increments the time circuits
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Fig 27. STOP bit release timing
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