RV-8523 Datasheet, PDF (42/57 Pages) MICORO CRYSTAL SWITZERLAND – Real Time Clock

Micro Crystal
Real Time Clock / Calendar Module
RV-8523
The lower two stages of the prescaler (F₀ and F₁) are not reset and because the I²C bus 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
figure below).
STOP bit release timing:
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 F₀ and F₁ not being reset (see table below).
First increment of the time circuits after STOP release:
Bit
STOP
Prescaler bits¹⁾
F0F1-F2 to F14
1 Hz Tick
Time
hh:mm:ss
Comment
Clock is running normally
0
01-0000111010100
12:45:12
Prescaler counting normally
STOP bit is activated by user; F0 and F1 are not reset and values cannot be predicted externally
1
XX-0000000000000
12:45:12
Prescaler is reset; time circuits are frozen
New time is set by user
1
XX-0000000000000
08:00:00
Prescaler is reset; time circuits are frozen
STOP is released by user
0
XX-0000000000000
08:00:00
Prescaler is now running
0
XX-1000000000000
08:00:00
-
0
XX-0100000000000
08:00:00
-
0
XX-1100000000000
08:00:00
-
:
:
:
:
0
11-1111111111110
08:00:00
-
0
00-0000000000001
0
10-0000000000001
08:00:01
08:00:01
0 to 1 transition of F14 increments the time circuits
-
:
:
:
:
0
11-1111111111111
08:00:01
-
0
00-0000000000000
08:00:01
-
:
:
:
-
0
11-1111111111110
08:00:01
-
0
00-0000000000001
08:00:02
0 to 1 transition of F14 increments the time circuits
1) _{F0 is clocked at 32.768 kHz.}
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