M41T256Y

14/27

Keys: S = Sign Bit

FT = Frequency Test Bit

ST = Stop Bit

WC = Write Clock Bit

X = '1' or '0'

BL = Battery Low Flag (Read only bit)

TB = Tamper Bit (Read only bit)

TEB = Tamper Enable Bit

0 = Must be set to '0'

SLP = Sleep Mode Bit

Note: 7FF0h through 7FF6h are invalid addresses and when read will return arbitrary data.

Address

Data

Function/Range

BCD Format

D7

D6

D5

D4

D3

D2

D1

D0

7FFFh

10 Years

Year

Year

00-99

7FFEh

0

0

0

10M

Month

Month

01-12

7FFDh

0

0

10 Date

Date: Day of Month

Date

01-31

7FFCh

BL

FT

TEB

TB

0

Day of Week

Tamper/Day

0-1/01-07

7FFBh

0

0

10 Hours

Hours (24 Hour Format)

Hours

00-23

7FFAh

0

10 Minutes

Minutes

Minutes

00-59

7FF9h

ST

10 Seconds

Seconds

Seconds

00-59

7FF8h

WC

SLP

S

Calibration

Control

7FF7h

0.1 Seconds

0.01 Seconds

Seconds

00-99

7FF6h

XXXX

XXXX

Reserved

7FF5h

XXXX

XXXX

Reserved

7FF4h

XXXX

XXXX

Reserved

7FF3h

XXXX

XXXX

Reserved

7FF2h

XXXX

XXXX

Reserved

7FF1h

XXXX

XXXX

Reserved

7FF0h

XXXX

XXXX

Reserved