DS1284/DS1286

4 of 18

PIN

DIP

EDIP

PLCC

NAME

FUNCTION

28

28

28

Primary Power-Supply Input. When voltage is applied within

normal limits, the device is fully accessible and data can be

written and read. When a backup supply is connected to the

However, the timekeeping function continues unaffected by the

lower input voltage.

Figure 1. Block Diagram

Internal Registers

Internal Counters

Internal Registers

Oscillator

÷ 8

÷ 40.96

÷ 40.96

PF delay

÷ 10

Update seconds through

years and check time of

day alarm

User RAM

50 Bytes

Command

Register

External Registers,

clock, calendar,

time of day alarm

Power

Switch

÷ 4

Swap

pins

External

Registers

Hundredths of

Seconds

External

Registers

Watchdog Alarm

Internal Counters

Data I/O Buffers

A0-A5

CE

OE

WE

V

CC

V

BAT

SQW

INTA

INTB/

(INTB)

1024Hz

TD INT

WD INT

DS1286

only

100Hz

100Hz

DS1286 only

GND

DQ0–DQ7

DS1284/DS1286

X1

X2

P

N

N

V

CC

IBH