PCF2129AT NXP [NXP Semiconductors], PCF2129AT Datasheet - Page 37

• Manufacturer Part Number: PCF2129AT
• Description: Integrated RTC, TCXO and quartz crystal
• Manufacturer: NXP [NXP Semiconductors]

NXP Semiconductors
PCF2129A_1
Product data sheet
Fig 19. Interrupt block diagram
When SI, MI, WD_CD, AIE, TSIE, BIE, BLIE are all disabled, INT will remain high-impedance.
SECONDS COUNTER
MINUTES COUNTER
8.12 Interrupt output, INT
watchdog counter
PCF2129A has an interrupt output pin INT which is open-drain, active LOW. Interrupts
may be sourced from different places:
circuit: clear BF
•
•
•
•
•
•
WATCHDOG
from interface:
from interface:
from interface:
from interface:
set timestamp
WD_CD = 1
COUNTER
low detection
MCU loading
low flag, BLF
from battery
second or minute timer
watchdog timer
alarm
timestamp
battery switch-over
battery low detection
set battery
set battery
flag, TSFx
clear TSF
clear MSF
set alarm
clear AF
clear BF
flag, AF
flag, BF
MI
SI
SET
SET
SET
SET
SET
TSFx: TIMESTAMP
BLF: BATTERY
SET
BF: BATTERY
SECOND FLAG
WATCHDOG
TIMER FLAG
AF: ALARM
LOW FLAG
WDTF:
CLEAR
CLEAR
CLEAR
CLEAR
CLEAR
MINUTE
FLAG
FLAG
FLAG
Rev. 01 — 13 January 2010
CLEAR
MSF:
TRIGGER
GENERATOR 1
to interface:
read MSF
to interface:
read WD_CD
to interface:
read AF
to interface:
read TSFx
to interface:
read BF
to interface:
read BLF
PULSE
CLEAR
Integrated RTC, TCXO and quartz crystal
0
1
TI_TP
WD_CD = 0
SI/MI
TSIE
BLIE
AIE
BIE
PCF2129A
001aaj399
© NXP B.V. 2010. All rights reserved.
INT pin
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