PCF2129T datasheet(39/73 Pages) NXP

39 / 73 page

PCF2129T

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 3 — 12 February 2013

39 of 73

NXP Semiconductors

PCF2129T

Accurate RTC with integrated quartz crystal for industrial

8.12 Interrupt output, INT

PCF2129T has an interrupt output pin INT which is open-drain, active LOW (requiring a

pull-up resistor if used). Interrupts may be sourced from different places:

• second or minute timer

• watchdog timer

• alarm

• timestamp

• battery switch-over

• battery low detection

When SI, MI, WD_CD, AIE, TSIE, BIE, BLIE are all disabled, INT will remain high-impedance (output HIGH).

Fig 19. Interrupt block diagram

BLF: BATTERY

LOW FLAG

SET

set battery

low flag, BLF

to interface:

read BLF

BLIE

001aaj399

from battery

low detection

circuit: clear BF

CLEAR

BF: BATTERY

FLAG

SET

set battery

flag, BF

to interface:

read BF

BIE

from interface:

clear BF

CLEAR

TSFx: TIMESTAMP

FLAG

SET

set timestamp

flag, TSFx

to interface:

read TSFx

TSIE

from interface:

clear TSF

CLEAR

AF: ALARM

FLAG

SET

set alarm

flag, AF

to interface:

read AF

AIE

from interface:

clear AF

CLEAR

WDTF:

WATCHDOG

TIMER FLAG

SET

WATCHDOG

COUNTER

to interface:

read WD_CD

WD_CD = 0

WD_CD = 1

MCU loading

watchdog counter

CLEAR

INT pin

MSF:

MINUTE

SECOND FLAG

SET

MINUTES COUNTER

SECONDS COUNTER

to interface:

read MSF

SI/MI

TI_TP

from interface:

clear MSF

CLEAR

PULSE

GENERATOR 1

TRIGGER

CLEAR

PCF2129T датащи(PDF) 39 Page - NXP Semiconductors

PCF2129T датащи(HTML) 39 Page - NXP Semiconductors

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73

датащи скачать

ссылки URL