PCF2129T View Datasheet(PDF) - NXP Semiconductors.
Part Name
Description
MFG CO.
'PCF2129T' PDF : 73 Pages View PDF
NXP Semiconductors
PCF2129T
Accurate RTC with integrated quartz crystal for industrial
8.9 Alarm function
When one or more of the alarm bit fields are loaded with a valid second, minute, hour, day,
or weekday and its corresponding alarm enable bit (AE_x) is logic 0, then that information
is compared with the actual second, minute, hour, day, and weekday (see Figure 15).
check now signal
SECOND ALARM
=
SECOND TIME
MINUTE ALARM
=
MINUTE TIME
AE_S
AE_M
example
AE_S = 1
1
0
HOUR ALARM
=
HOUR TIME
AE_H
set alarm flag AF (1)
DAY ALARM
=
DAY TIME
AE_D
WEEKDAY ALARM
=
WEEKDAY TIME
AE_W
013aaa236
(1) Only when all enabled alarm settings are matching.
Fig 15. Alarm function block diagram
The generation of interrupts from the alarm function is described in Section 8.12.4.
8.9.1 Register Second_alarm
Table 26. Second_alarm - second alarm register (address 0Ah) bit description
Bit Symbol
Value Place value Description
7
AE_S
0
-
second alarm is enabled
1[1]
-
second alarm is disabled
6 to 4 SECOND_ALARM
3 to 0
0 to 5
0 to 9
ten’s place second alarm information coded in BCD
unit place format
[1] Default value.
PCF2129T
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 12 February 2013
© NXP B.V. 2013. All rights reserved.
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