pcf2127a NXP Semiconductors, pcf2127a Datasheet - Page 45

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

NXP Semiconductors
PCF2127A_1
Product data sheet
Fig 25. Interrupt block diagram
When SI, MI, CDTIE, WD_CD, AIE, TSIE, BIE, BLIE are all disabled, INT will remain high-impedance.
8.13.1.1 Minute and second interrupts
SECONDS COUNTER
MINUTES COUNTER
8.13.1 Minute, second and countdown timer interrupts
watchdog counter
Minute and second interrupts are generated by predefined timers. The timers can be
enabled independently from one another by the bits MI and SI in register Control_1.
However, a minute interrupt enabled on top of a second interrupt will not be
distinguishable since it will occur at the same time.
WD_CD[1:0] = 01
circuit: clear BF
WD_CD[1:0] = 01
WATCHDOG
from interface:
from interface:
from interface:
set timestamp
COUNTDOWN
COUNTER
low detection
MCU loading
low flag, BLF
from interface:
from interface:
from battery
COUNTER
clear TSFx
set battery
set battery
flag, TSFx
clear CDTF
set alarm
clear MSF
clear AF
clear BF
flag, AF
flag, BF
MI
SI
SET
SET
TSFx: TIMESTAMP
SET
SET
SET
SET
SET
BLF: BATTERY
SECOND FLAG
BF: BATTERY
COUNTDOWN
WATCHDOG
TIMER FLAG
TIMER FLAG
AF: ALARM
LOW FLAG
MINUTE
Rev. 01 — 21 January 2010
WDTF:
CLEAR
CLEAR
CLEAR
CLEAR
CLEAR
CLEAR
CLEAR
CDTF:
FLAG
FLAG
FLAG
MSF:
TRIGGER
TRIGGER
GENERATOR 1
GENERATOR 2
to interface:
read MSF
to interface:
read CDTF
to interface:
read WDTF
to interface:
read AF
to interface:
read TSFx
to interface:
read BF
to interface:
read BLF
PULSE
PULSE
CLEAR
CLEAR
Integrated RTC, TCXO and quartz crystal
TI_TP
0
1
0
1
WD_CD[1:0] = 00
CDTIE
001aag070
SI/MI
TSIE
BLIE
AIE
BIE
PCF2127A
© NXP B.V. 2010. All rights reserved.
INT pin
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