pcf2127a NXP Semiconductors, pcf2127a Datasheet - Page 7

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

NXP Semiconductors
Table 4.
Bit positions labelled as - are not implemented and will return a 0 when read. Bit T must always be written with logic 0. Bits
labeled as X are undefined at power-on and unchanged by subsequent resets.
PCF2127A_1
Product data sheet
Address Register name
Control registers
00h
01h
02h
Time and date registers
03h
04h
05h
06h
07h
08h
09h
Alarm registers
0Ah
0Bh
0Ch
0Dh
0Eh
CLKOUT control register
0Fh
Watchdog registers
10h
11h
Timestamp registers
12h
13h
14h
15h
16h
17h
18h
Crystal aging register
19h
Control_1
Control_2
Control_3
Seconds
Minutes
Hours
Days
Weekdays
Months
Years
Second_alarm
Minute_alarm
Hour_alarm
Day_alarm
Weekday_alarm
CLKOUT_ctl
Watchdg_tim_ctl
Watchdg_tim_val WATCHDG_TIM_VAL[7:0]
Timestp_ctl
Sec_timestp
Min_timestp
Hour_timestp
Day_timestp
Mon_timestp
Year_timestp
Aging_offset
Register overview
Bit
7
EXT_
TEST
PWRMNG[2:0]
OSF
-
-
-
-
-
YEARS (0 to 99)
AEN_M MINUTE_ALARM (0 to 59)
AEN_H
AEN_D
AEN_W -
TCR[1:0]
WD_CD[1:0]
TSM
-
-
-
MSF
AEN_S
-
-
YEAR_TIMESTP (0 to 99)
-
WDTF
SECONDS (0 to 59)
MINUTES (0 to 59)
-
-
-
SECOND_ALARM (0 to 59)
-
-
TSOFF
MINUTE_TIMESTP (0 to 59)
-
-
6
T
-
-
SECOND_TIMESTP (0 to 59)
-
-
Rev. 01 — 21 January 2010
TSF2
AMPM
DAYS (1 to 31)
AMPM
DAY_ALARM (1 to 31)
-
DAY_TIMESTP (1 to 31)
5
STOP
HOURS (0 to 23) in 24 h mode
-
-
HOUR_ALARM (0 to 23) in 24 h mode
-
-
TI_TP
AMPM
HOUR_TIMESTP (0 to 23) in 24 h mode
-
-
HOURS (1 to 12) in 12 h mode
HOUR_ALARM (1 to 12) in 12 h mode
1_O_16_TIMESTP[4:0]
4
TSF1
AF
BTSE
-
MONTHS (1 to 12)
-
-
-
HOUR_TIMESTP (1 to 12) in 12 h mode
MONTH_TIMESTP (1 to 12)
-
3
POR_
OVRD
CDTF
BF
-
-
-
-
AO[3:0]
Integrated RTC, TCXO and quartz crystal
2
12_24
TSIE
BLF
WEEKDAYS (0 to 6)
WEEKDAY_ALARM (0 to 6) 1 - - - - XXX
COF[2:0]
-
1
MI
AIE
BIE
TF[1:0]
PCF2127A
0
SI
CDTIE
BLIE
© NXP B.V. 2010. All rights reserved.
1 - XX XXXX
Reset value
0000 0000
0000 0000
0000 0000
1XXX XXXX
- XXX XXXX
- - XX XXXX
- - XX XXXX
- - XX XXXX
- - - - - XXX
- - - X XXXX
XXXX XXXX
1XXX XXXX
1XXX XXXX
1 - XX XXXX
1 - XX XXXX
00 - - - 000
000 - - - 11
XXXX XXXX
00 - X XXXX
- XXX XXXX
- XXX XXXX
- - XX XXXX
- - XX XXXX
- - XX XXXX
- - - X XXXX
XXXX XXXX
- - - - 1000
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