PCF8523 NXP [NXP Semiconductors], PCF8523 Datasheet - Page 41

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

NXP Semiconductors
PCF8523
Product data sheet
8.10 STOP bit function
The STOP bit function allows the accurate starting of the time circuits. The STOP bit
function will cause the upper part of the prescaler (F
no 1 Hz ticks will be generated. The time circuits can then be set and will not increment
until the STOP bit is released (see
STOP will not affect the output of 32.768 kHz, 16.384 kHz or 8.192 kHz (see
Section
The lower two stages of the prescaler (F
interface is asynchronous to the crystal oscillator, the accuracy of re-starting the time
circuits will be between 0 and one 8.192 kHz cycle (see
The first increment of the time circuits is between 0.499878 s and 0.500000 s after stop is
released. The uncertainty is caused by the prescaler bits F
Table
Fig 25. STOP bit
Fig 26. STOP bit release timing
43).
OSC
8.9.1.1).
stop released
All information provided in this document is subject to legal disclaimers.
8192 Hz
Rev. 3 — 30 March 2011
F
0
Figure
F
1
DETECTOR
OSC STOP
0
and F
25).
0 μs to 122 μs
RES
F
1
2
) are not reset and because the I
Real-Time Clock (RTC) and calendar
16384 Hz
8192 Hz
oscillator stop flag
2
512 Hz
to F
Figure
14
0
) to be held in reset and thus
and F
RES
F
13
26).
1
CLKOUT source
not being reset (see
RES
F
PCF8523
001aaf912
© NXP B.V. 2011. All rights reserved.
14
013aaa336
1 Hz tick
stop
2
C-bus
41 of 66