Datasheet
PCF85063TP All information provided in this document is subject to legal disclaimers. © NXP B.V. 2013. All rights reserved.
Product data sheet Rev. 3 — 11 July 2013 21 of 47
NXP Semiconductors
PCF85063TP
Tiny Real-Time Clock/calendar
Because 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 will 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.
Recommended method for reading the time:
1. Send a START condition and the slave address (see Table 29 on page 24
) for write
(A2h)
2. Set the address pointer to 4 (Seconds) by sending 04h
3. Send a RESTART condition or STOP followed by START
4. Send the slave address for read (A3h)
5. Read Seconds
6. Read Minutes
7. Read Hours
8. Read Days
9. Read Weekdays
10. Read Months
11. Read Years
12. Send a STOP condition
Fig 12. Access time for read/write operations
DDD
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