PCF2129AT/2,518 NXP Semiconductors, PCF2129AT/2,518 Datasheet - Page 43

• Manufacturer Part Number: PCF2129AT/2,518
• Description: Real Time Clock
• Manufacturer: NXP Semiconductors
• Series: PCF2129r

Specifications of PCF2129AT/2,518

• Rohs: yes
• Function: Clock, Calendar, Alarm, Watchdog, Timestamp
• Rtc Bus Interface: I2C, SPI
• Date Format: Binary
• Time Format: Binary
• Supply Voltage - Max: 4.2 V
• Supply Voltage - Min: 1.2 V
• Maximum Operating Temperature: + 60 C
• Minimum Operating Temperature: - 15 C
• Mounting Style: SMD/SMT
• Package / Case: SOP-20
• Battery Backup Switching: Yes
• Factory Pack Quantity: 2000

NXP Semiconductors
Table 47.
[1]
PCF2129AT
Product data sheet
Bit
STOP
Clock is running normally
0
STOP bit is activated by user. F
1
New time is set by user
1
STOP bit is released by user
0
0
0
0
:
0
0
0
:
0
0
0
:
0
0
F
0
is clocked at 32.768 kHz.
Prescaler bits
F
010000111-010100
xxxxxxxxx-000000
xxxxxxxxx-000000
xxxxxxxxx-000000
xxxxxxxxx-100000
xxxxxxxxx-100000
xxxxxxxxx-110000
:
111111111-111110
000000000-000001
100000000-000001
:
111111111-111111
000000000-000000
100000000-000000
:
111111111-111110
000000000-000001
First increment of time circuits after stop release
0
to F
8.14 STOP bit function
8
- F
9
to F
The function of the STOP bit is to allow for accurate starting of the time circuits. STOP will
cause the upper part of the prescaler (F
are generated. The time circuits can then be set and will not increment until the STOP bit
is released. STOP will not affect the CLKOUT signal but the output of the prescaler in the
range of 32 Hz to 1 Hz (see
The lower stages of the prescaler, F
SPI-bus are asynchronous to the crystal oscillator, the accuracy of restarting the time
circuits is between 0 and one 64 Hz cycle (0.484375 s and 0.500000 s), see
Figure
[1]
14
25.
0
to F
1 Hz tick
8
001aaj479
are not reset and values cannot be predicted externally
All information provided in this document is subject to legal disclaimers.
Rev. 5 — 12 February 2013
Time
hh:mm:ss
12:45:12
12:45:12
08:00:00
08:00:00
08:00:00
08:00:00
08:00:00
:
08:00:00
08:00:01
08:00:01
:
08:00:01
08:00:01
:
08:00:01
08:00:02
Figure
24).
0
to F
Comment
prescaler counting normally
prescaler is reset; time circuits are frozen
prescaler is reset; time circuits are frozen
prescaler is now running
0 to 1 transition of F
0 to 1 transition of F
9
8
to F
, are not reset and because the I
14
Integrated RTC, TCXO and quartz crystal
) to be held in reset and thus no 1 Hz ticks
14
14
increments the time circuits
increments the time circuits
PCF2129AT
© NXP B.V. 2013. All rights reserved.
2
C-bus and the
Table 47
43 of 73
and