pcf2127a NXP Semiconductors, pcf2127a Datasheet - Page 34

• Manufacturer Part Number: pcf2127a
• Description: Integrated Rtc, Tcxo And Quartz Crystal
• Manufacturer: NXP Semiconductors

NXP Semiconductors
PCF2127A_1
Product data sheet
8.10.4 Register Day_alarm
8.10.5 Register Weekday_alarm
8.10.6 Alarm flag
Table 32.
[1]
Table 33.
[1]
When all enabled comparisons first match, the alarm flag AF (register Control_2) is set.
AF will remain set until cleared by using the interface. Once AF has been cleared it will
only be set again when the time increments to match the alarm condition once more. For
clearing the flags see
Alarm registers which have their alarm enable bit AE_x at logic 1 are ignored.
Bit
7
6
5 to 4 DAY_ALARM
3 to 0
Bit
7
6 to 3 -
2 to 0 WEEKDAY_ALARM
Fig 20. Alarm flag timing diagram
Default value.
Default value.
Symbol
AE_D
-
Symbol
AE_W
Example where only the minute alarm is used and no other interrupts are enabled.
Day_alarm - day rearm register (address 0Dh) bit description
Weekday_alarm - weekday alarm register (address 0Eh) bit description
INT when AIE = 1
minutes counter
minute alarm
Rev. 01 — 21 January 2010
Section 8.11.6
AF
Value
0
1
-
0 to 3
0 to 9
[1]
Value
0
1
-
0 to 6
[1]
44
45
Description
weekday alarm is enabled
weekday alarm is disabled
unused
Place value Description
-
-
-
ten’s place
unit place
weekday alarm information
Integrated RTC, TCXO and quartz crystal
day alarm is enabled
day alarm is disabled
unused
day alarm information coded in BCD
format
45
PCF2127A
001aaf903
46
© NXP B.V. 2010. All rights reserved.
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