PCA2129T/Q900/2,51 NXP Semiconductors, PCA2129T/Q900/2,51 Datasheet - Page 34

• Manufacturer Part Number: PCA2129T/Q900/2,51
• Description: Real Time Clock
• Manufacturer: NXP Semiconductors
• Series: PCA2129r

Specifications of PCA2129T/Q900/2,51

• 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: 1.8 V
• Maximum Operating Temperature: + 80 C
• Minimum Operating Temperature: - 30 C
• Mounting Style: SMD/SMT
• Package / Case: SOP-16
• Battery Backup Switching: Yes

NXP Semiconductors
PCA2129T
Product data sheet
8.11.1 Timestamp flag
8.11 Timestamp function
The PCA2129T has an active LOW timestamp input pin TS, internally pulled with an
on-chip pull-up resistor to the internal power supply of the device. It also has a timestamp
detection circuit which can detect two different events:
The timestamp function is enabled by default after power-on and it can be switched off by
setting the control bit TSOFF (register Timestp_ctl).
A most common application of the timestamp function is described in
See
1. Input on pin TS is driven to an intermediate level between power supply and ground.
2. Input on pin TS is driven to ground.
1. When the TS input pin is driven to an intermediate level between the power supply
2. When the TS input pin is driven to ground, the following sequence occurs:
Fig 18. Timestamp detection with two push-buttons on the TS pin (
and ground, then the following sequence occurs:
a. The actual date and time are stored in the timestamp registers.
b. The timestamp flag TSF1 (register Control_1) is set.
c. If the TSIE bit (register Control_2) is active, an interrupt on the INT pin is
The TSF1 flag can be cleared by command. Clearing the flag will clear the interrupt.
Once TSF1 is cleared, it will only be set again when a new negative edge on pin TS is
detected.
a. The actual date and time are stored in the timestamp registers.
b. In addition to the TSF1 flag, the TSF2 flag (register Control_2) is set.
c. If the TSIE bit is active, an interrupt on the INT pin is generated.
Section 8.12.5
generated.
tamper detection)
All information provided in this document is subject to legal disclaimers.
push-button 2
connected to
cover 2
for a description of interrupt generation from the timestamp function.
Rev. 3 — 24 January 2013
Accurate RTC with integrated quartz crystal for automotive
push-button 1
connected to
cover 1
V
SS
R2 =
220 kΩ
± 5 %
TS
1
2
3
4
5
6
7
8
PCA2129T
V
DD
R1 =
220 kΩ
(typ)
013aaa527
for example,
PCA2129T
16
15
14
13
12
10
11
9
Ref. 3
© NXP B.V. 2013. All rights reserved.
“AN11120”.
for
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