IDT1337

REA LTIME CLOCK WITH SERIAL INTERFACE

RTC

5

IDT1337

REV J 111009

Address Map

Table 2 (Timekeeper Registers) shows the address map for the IDT1337 registers. During a multibyte access, when the

address pointer incrementing to location 00h, the current time is transferred to a second set of registers. The time

information is read from these secondary registers, while the clock may continue to run. This eliminates the need to re-read

the registers in case of an update of the main registers during a read.

Table 1. Timekeeper Registers

Note: Unless otherwise specified, the state of the registers are not defined when power is first applied or when VCC falls below the

min

Address

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Function

Range

00h

0

10 seconds

Seconds

Seconds

00 - 59

01h

0

10 minutes

Minutes

Minutes

00 - 59

02h

0

12/24

AM/PM

10 hour

Hour

Hours

1 - 12 +

AM/PM

00 - 23

10 hour

03h

0

0000

Day

Day

1 - 7

04h

0

0

10 date

Date

Date

01 - 31

05h

Century

0

0

10 month

Month

Month/Century

01 - 12 +

Century

06h

10 year

Year

Year

00 - 99

07h

A1M1

10 seconds

Seconds

Alarm 1

Seconds

00 - 59

08h

A1M2

10 minutes

Minutes

Alarm 1

Minutes

00 - 59

09h

A1M3

12/24

AM/PM

10 hour

Hour

Alarm 1 Hours

1 - 12 +

AM/PM

00 - 23

10 hour

0Ah

A1M4

DY/DT

10 date

Day,

Alarm 1 Day

1 - 7

Date

Alarm 1 Date

1 - 31

0Bh

A2M2

10 minutes

Minutes

Alarm 2

Minutes

00 - 59

0Ch

A2M3

12/24

AM/PM

10 hour

Hour

Alarm 2 Hours

1 - 12 +

AM/PM

00 - 23

10 hour

0Dh

A2M4

DY/DT

10 date

Day,

Alarm 2 Day

1 - 7

Date

Alarm 2 Date

1 - 31

0Eh

EOSC

0

0

RS2

RS1

INTCN

A2IE

A1IE

Control

0Fh

OSF

00000

A2F

A1F

Status