DS1287A データシートの表示（PDF） - Dallas Semiconductor -> Maxim Integrated

部品番号

コンポーネント説明

一致するリスト

DS1287A

Real-Time Clock

Dallas Semiconductor -> Maxim Integrated 

DS1287A

DS1287A

Real Time Clock

FEATURES

• Drop-in replacement for IBM AT computer clock/ca-

lendar

• Pin compatible with the MC146818A

• Totally nonvolatile with over 10 years of operation in

the absence of power

• Self-contained subsystem includes lithium, quartz,

and support circuitry

• Counts seconds, minutes, hours, day of the week,

date, month, and year with leap year compensation

• Binary or BCD representation of time, calendar, and

alarm

• 12- or 24-hour clock with AM and PM in 12-hour mode

• Daylight Savings Time option

• Selectable between Motorola and Intel bus timing

• Multiplex bus for pin efficiency

• Interfaced with software as 64 RAM locations

– 14 bytes of clock and control registers

– 50 bytes of general purpose RAM

• Programmable square wave output signal

• Bus-compatible interrupt signals (IRQ)

• Three interrupts are separately software-maskable

and testable

– Time-of-day alarm once/second to once/day

– Periodic rates from 122 ms to 500 ms

– End of clock update cycle

PIN ASSIGNMENT

MOT 1

NC 2

NC 3

AD0 4

AD1 5

AD2 6

AD3 7

AD4 8

AD5 9

AD6 10

AD7 11

GND 12

24 VCC

23 SQW

22 NC

21 RCLR

20 NC

19 IRQ

18 RESET

17 DS

16 NC

15 R/W

14 AS

13 CS

24 PIN ENCAPSULATED PACKAGE

PIN DESCRIPTION

AD0–AD7

NC

MOT

CS

AS

R/W

DS

RESET

IRQ

drain)

SQW

VCC

GND

RCLR

- Multiplexed address/data bus

- No connection

- Bus type selection

- Chip select

- Address strobe

- Read/write input

- Data strobe

- Reset input

- Interrupt request output (open

- Square wave output

- +5 volt supply

- Ground

- RAM clear

DESCRIPTION

The DS1287A is identical to the DS1287 with the addi-

tion of the RAM clear pin. For a complete description of

operating conditions, electrical and mechanical charac-

teristics, bus timing, and pin descriptions see the

DS12887A data sheet.

022798 1/1

Share Link: