pcf8564a NXP Semiconductors, pcf8564a Datasheet - Page 19

• Manufacturer Part Number: pcf8564a
• Description: Real Time Clock And Calendar
• Manufacturer: NXP Semiconductors

NXP Semiconductors
Table 26.
[1]
PCF8564A_1
Product data sheet
Bit
STOP
Clock is running normally
0
STOP bit is activated by user. F
1
New time is set by user
1
STOP bit is released by user
0
F
0
is clocked at 32.768 kHz.
Prescaler bits
F
01-0 0001 1101 0100
XX-0 0000 0000 0000
XX-0 0000 0000 0000
XX-0 0000 0000 0000
XX-1 0000 0000 0000
XX-0 1000 0000 0000
XX-1 1000 0000 0000
:
11-1 1111 1111 1110
00-0 0000 0000 0001
10-0 0000 0000 0001
:
11-1 1111 1111 1111
00-0 0000 0000 0000
10-0 0000 0000 0000
:
11-1 1111 1111 1110
00-0 0000 0000 0001
First increment of time circuits after STOP bit release
0
F
1
-F
8.11 Reset
2
to F
14
The first increment of the time circuits is between 0.507813 s and 0.507935 s after STOP
bit is released. The uncertainty is caused by the prescaler bits F
(see
The PCF8564A includes an internal reset circuit which is active whenever the oscillator is
stopped. In the reset state the I
all registers are set according to
reset.
Table
[1]
0
F
1
26) and the unknown state of the 32 kHz clock.
are not reset and values cannot be predicted externally
1 Hz tick
013aaa076
Rev. 1 — 8 October 2009
Time
hh:mm:ss
12:45:12
12:45:12
08:00:00
08:00:00
08:00:00
08:00:00
08:00:00
:
08:00:00
08:00:01
08:00:01
:
08:00:01
08:00:01
08:00:01
:
08:00:01
08:00:02
2
C-bus logic is initialized including the address pointer and
Table
27. I
Comment
prescaler counting normally
prescaler is reset; time circuits are frozen
prescaler is reset; time circuits are frozen
prescaler is now running
-
-
-
:
-
0 to 1 transition of F
-
:
-
-
-
-
-
0 to 1 transition of F
2
C-bus communication is not possible during
Real time clock and calendar
14
14
increments the time circuits
increments the time circuits
0
and F
PCF8564A
© NXP B.V. 2009. All rights reserved.
1
not being reset
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