PCA2125TS NXP [NXP Semiconductors], PCA2125TS Datasheet - Page 23

• Manufacturer Part Number: PCA2125TS
• Description: SPI Real-time clock/calendar
• Manufacturer: NXP [NXP Semiconductors]

NXP Semiconductors
Table 36.
[1]
PCA2125_1
Product data sheet
Bit STOP
Clock is running normally
0
Stop is activated by user. F0F1 are not reset and values can not be predicted externally
1
New time is set by user
1
Stop is released by user
0
F
0
is clocked at 32.768 kHz.
Example: first increment of time circuits after stop release
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
0
F
1
-F
2
to F
The first increment of the time circuits is between 0.499888 s and 0.500000 s after stop is
released. The uncertainty is caused by prescaler bits F0 and F1 not being reset;
see
14
Fig 17. Increment of time circuit
[1]
Table
36.
1 Hz tick
0.499888 s to 0.500000 s
Rev. 01 — 28 July 2008
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
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 F14 increments the time circuits
0 to 1 transition of F14 increments the time circuits
1 s
SPI Real-time clock/calendar
001aaf913
PCA2125
© NXP B.V. 2008. All rights reserved.
23 of 36