User Manual

MAX6901
then read the Seconds register again (final-seconds).
Check to see that final-seconds is equal to initial-sec-
onds. If not, repeat the write process. If the Seconds
register is to be written, update the Seconds register
first, and then read it back and store its value (initial-
seconds). Update the remaining timekeeping registers
and then read the Seconds register again (final-sec-
3-Wire Serial RTC in a TDFN
6 _______________________________________________________________________________________
Table 2. Register Address/Definition
REGISTER ADDRESS REGISTER DEFINITION
FUNCTION A7 A6 A5 A4 A3 A2 A1 A0 VALUE D7 D6 D5 D4 D3 D2 D1 D0
TIMEKEEPING
00-59
32kHz
EN
10 SEC 1 SEC
SECOND
1000000
RD
/W
*POR STATE 0 0 0 0 0000
00-59
ALM
OUT
10 MIN 1 MIN
MINUTE
1000001
RD
/W
*POR STATE
0 0000000
00-23 12/24
10
HR
HOUR
1000010
RD
/W
01-12 1/0
0
A/P
0/1
10
HR
1 HR
*POR STATE 0 0 0 00000
01-28/29
01-30
01-31
0 0 10 DATE 1 DATE
DATE
1000011
RD
/W
*POR STATE
0 0 000001
01-12 0 0 0 10M 1 MONTH
MONTH
1000100
RD
/W
*POR STATE
0 0 0 00001
01-07 0 0 0 0 0 WEEKDAY
DAY
1000101
RD
/W
*POR STATE
0 0 0 0 0 001
00-99 10 YEAR 1 YEAR
YEAR
1000110
RD
/W
*POR STATE 0 1 1 1 0 0 0 0
WP 0 0 0 0 0 0 0
CONTROL
1000111
RD
/W
*POR STATE 0
0 0 0 0 0 0 0
00-99 1000 YEAR 100 YEAR
CENTURY
1001001
RD
/W
*POR STATE 0 0 0 1 1 0 0 1
Note: *POR STATE
defines power-on reset state of register content.