PCF2127AT/1 NXP [NXP Semiconductors], PCF2127AT/1 Datasheet - Page 45

• Manufacturer Part Number: PCF2127AT/1
• Description: Integrated RTC, TCXO and quartz crystal
• Manufacturer: NXP [NXP Semiconductors]

NXP Semiconductors
PCF2127A_2
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.
SECONDS COUNTER
MINUTES COUNTER
8.13 Interrupt output, INT
watchdog counter
PCF2127A has an interrupt output pin INT which is open-drain, active LOW. Interrupts
may be sourced from different places:
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
second or minute timer
countdown timer
clear TSFx
set battery
set battery
flag, TSFx
clear CDTF
set alarm
clear MSF
clear AF
clear BF
flag, AF
flag, BF
MI
SI
All information provided in this document is subject to legal disclaimers.
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
WDTF:
CLEAR
CLEAR
CLEAR
CLEAR
CLEAR
CLEAR
CLEAR
CDTF:
FLAG
FLAG
FLAG
MSF:
Rev. 02 — 7 May 2010
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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