Clock operation

M41T256Y

18/30

Table 3.

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.

3.4

Power-on reset

should be chosen to control rise time.

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

XXXXX

XXX

Reserved

7FF5h

XXXXX

XXX

Reserved

7FF4h

XXXXX

XXX

Reserved

7FF3h

XXXXX

XXX

Reserved

7FF2h

XXXXX

XXX

Reserved

7FF1h

XXXXX

XXX

Reserved

7FF0h

XXXXX

XXX

Reserved