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
26&
+]
/2:(535(6&$/(5
+]
+] +] +]
)
)
)
)
Fig 33. STOP bit functional diagram
833(535(6&$/(5
+]
)
)
)
5(6 5(6
5(6
)
5(6
+]WLFN
VWRS
DDM
The lower stages of the prescaler, F0 to F8, are not reset and because the I2C-bus and the
SPI-bus are asynchronous to the crystal oscillator, the accuracy of restarting the time
circuits is between 0 and one 64 Hz cycle (0.484375 s and 0.500000 s), see Table 84 and
Figure 34.
Table 84. First increment of time circuits after stop release
Bit
STOP
Prescaler bits[1]
F0 to F8 - F9 to F14
Clock is running normally
1 Hz tick
Time
hh:mm:ss
Comment
0
010000111-010100
12:45:12
prescaler counting normally
STOP bit is activated by user. F0 to F8 are not reset and values cannot be predicted externally
1
xxxxxxxxx-000000
12:45:12
prescaler is reset; time circuits are frozen
New time is set by user
1
xxxxxxxxx-000000
08:00:00
prescaler is reset; time circuits are frozen
STOP bit is released by user
0
xxxxxxxxx-000000
08:00:00
prescaler is now running
0
xxxxxxxxx-100000
08:00:00
0
xxxxxxxxx-100000
08:00:00
0
xxxxxxxxx-110000
08:00:00
:
:
:
0
111111111-111110
08:00:00
0
000000000-000001
0
100000000-000001
08:00:01
08:00:01
0 to 1 transition of F14 increments the time circuits
:
:
:
0
111111111-111111
08:00:01
0
000000000-000000
08:00:01
0
100000000-000000
:
:
:
0
111111111-111110
08:00:01
0
000000000-000001
08:00:02
0 to 1 transition of F14 increments the time circuits
DDM
[1] F0 is clocked at 32.768 kHz.
PCF2127
Product data sheet
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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