PCA2129T/Q900/2,51 NXP Semiconductors, PCA2129T/Q900/2,51 Datasheet - Page 26

• 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
After this read/write access is completed, the time circuit is released again. Any pending
request to increment the time counters that occurred during the read/write access is
serviced. A maximum of 1 request can be stored; therefore, all accesses must be
completed within 1 second (see
As a consequence of this method, it is very important to make a read or write access in
one go, that is, setting or reading seconds through to years should be made in one single
access. Failing to comply with this method could result in the time becoming corrupted.
As an example, if the time (seconds through to hours) is set in one access and then in a
second access the date is set, it is possible that the time may increment between the two
accesses. A similar problem exists when reading. A roll-over may occur between reads
thus giving the minutes from one moment and the hours from the next. Therefore it is
advised to read all time and date registers in one access.
Fig 13. Data flow of the time function
Fig 14. Access time for read/write operations
START
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 24 January 2013
SLAVE ADDRESS
12_24 hour mode
CALCULATION
LEAP YEAR
Accurate RTC with integrated quartz crystal for automotive
Figure
14).
DATA
SECONDS
MINUTES
MONTHS
1 Hz tick
HOURS
YEARS
DAYS
DATA
t < 1 s
WEEKDAY
001aaf901
PCA2129T
STOP
© NXP B.V. 2013. All rights reserved.
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