PCF8563BS/4 View Datasheet(PDF) - NXP Semiconductors.
Part Name
Description
MFG CO.
'PCF8563BS/4' PDF : 45 Pages View PDF
NXP Semiconductors
PCF8563
Real-time clock/calendar
5. Apply 32 clock pulses to CLKOUT.
6. Read time registers to see the first change.
7. Apply 64 clock pulses to CLKOUT.
8. Read time registers to see the second change.
Repeat steps 7 and 8 for additional increments.
8.10 STOP bit function
The function of the STOP bit is to allow for accurate starting of the time circuits. The STOP
bit function will cause the upper part of the prescaler (F2 to F14) to be held in reset and
thus no 1 Hz ticks will be generated (see Figure 11). The time circuits can then be set and
will not increment until the STOP bit is released (see Figure 12 and Table 26).
OSCILLATOR STOP
DETECTOR
reset
OSCILLATOR
F0
F1
F2
RESET
F13
RESET
F14
RESET
1 Hz tick
STOP
Fig 11. STOP bit functional diagram
1 Hz
32 Hz
1024 Hz
32768 Hz
CLKOUT source
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The STOP bit function will not affect the output of 32.768 kHz on CLKOUT, but will stop
the generation of 1.024 kHz, 32 Hz, and 1 Hz.
The lower two stages of the prescaler (F0 and F1) are not reset; and because the I2C-bus
is asynchronous to the crystal oscillator, the accuracy of re-starting the time circuits will be
between zero and one 8.192 kHz cycle (see Figure 12).
8192 Hz
stop released
Fig 12. STOP bit release timing
0 μs to 122 μs
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PCF8563
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 9 — 16 June 2011
© NXP B.V. 2011. All rights reserved.
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