PCF2127 View Datasheet(PDF) - NXP Semiconductors.
Part Name
Description
MFG CO.
'PCF2127' PDF : 101 Pages View PDF
NXP Semiconductors
PCF2127
Accurate RTC with integrated quartz crystal for industrial applications
8.9.7 Register Years
Table 42. Years - years register (address 09h) bit allocation
Bits labeled as X are undefined at power-on and unchanged by subsequent resets.
Bit
7
6
5
4
3
2
1
0
Symbol
YEARS (0 to 99)
Reset
value
X
X
X
X
X
X
X
X
Table 43. Years - years register (address 09h) bit description
Bits labeled as X are undefined at power-on and unchanged by subsequent resets.
Bit
Symbol
Value
Place value Description
7 to 4
YEARS
0 to 9
ten’s place actual year coded in BCD format
3 to 0
0 to 9
unit place
8.9.8 Setting and reading the time
Figure 19 shows the data flow and data dependencies starting from the 1 Hz clock tick.
During read/write operations, the time counting circuits (memory locations 03h through
09h) are blocked.
This prevents
• Faulty reading of the clock and calendar during a carry condition
• Incrementing the time registers during the read cycle
PCF2127
Product data sheet
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Fig 19. Data flow of the time function
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 Figure 20).
All information provided in this document is subject to legal disclaimers.
Rev. 8 — 19 December 2014
© NXP Semiconductors N.V. 2014. All rights reserved.
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