PCF8523 NXP [NXP Semiconductors], PCF8523 Datasheet - Page 22

• Manufacturer Part Number: PCF8523
• Description: Real-Time Clock (RTC) and calendar
• Manufacturer: NXP [NXP Semiconductors]

NXP Semiconductors
PCF8523
Product data sheet
8.6.7 Register Years
8.6.8 Data flow of the time function
Table 19.
Figure 13
During read/write operations, the time counting circuits (memory locations 03h through
09h) are blocked.
This prevents:
After this read/write-access is completed, the time circuit is released again and any
pending request to increment the time counters that occurred during the read/write access
is serviced. A maximum of one request can be stored; therefore, all accesses must be
completed within 1 second (see
Bit
7 to 4
3 to 0
Fig 13. Data flow diagram of the time function
Fig 14. Access time for read/write operations
•
•
Faulty reading of the clock and calendar during a carry condition,
Incrementing the time registers during the read cycle.
Symbol
YEARS
shows the data flow and data dependencies starting from the 1 Hz clock tick.
Years - years register (09h) bit description
START
All information provided in this document is subject to legal disclaimers.
SLAVE ADDRESS
Rev. 3 — 30 March 2011
12/24 hour mode
CALCULATION
LEAP YEAR
Value
0 to 9
0 to 9
Figure
14).
DATA
SECONDS
MINUTES
MONTHS
1 Hz tick
HOURS
YEARS
DAYS
Place value Description
ten’s place
unit place
Real-Time Clock (RTC) and calendar
DATA
t < 1 s
WEEKDAYS
actual year coded in BCD format
013aaa324
STOP
PCF8523
© NXP B.V. 2011. All rights reserved.
013aaa215
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