DS1337 I
2
C Serial Real-Time Clock
ADDRESS MAP
shows the address map for the DS1337 registers. During a multibyte access, when the address pointer
reaches the end of the register space (0Fh) it wraps around to location 00h. On an I
2
C START, STOP, or 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 2. Timekeeper Registers
ADDRESS
00H
01H
02H
03H
04H
05H
06H
07H
08H
09H
A1M1
A1M2
A1M3
12/24
BIT 7
0
0
0
0
0
Century
12/24
0
0
0
10 Year
10 Seconds
10 Minutes
AM/PM
10 Hour
10 Hour
0
BIT 6
BIT 5
10 Seconds
10 Minutes
AM/PM
10 Hour
0
10 Date
10 Month
0
0
Date
Month
Year
Seconds
Minutes
Hour
Day
0AH
A1M4
DY/DT
10 Date
Date
0BH
0CH
A2M2
A2M3
12/24
10 Minutes
AM/PM
10 Hour
10 Hour
Minutes
Hour
Day
0DH
A2M4
DY/DT
10 Date
Date
0EH
0FH
EOSC
OSF
0
0
0
0
RS2
0
RS1
0
INTCN
0
A2IE
A2F
A1IE
A1F
Day
Day
Date
Month/
Century
Year
Alarm 1
Seconds
Alarm 1
Minutes
Alarm 1
Hours
Alarm 1
Day
Alarm 1
Date
Alarm 2
Minutes
Alarm 2
Hours
Alarm 2
Day
Alarm 2
Date
Control
Status
10 Hour
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
FUNCTION
Seconds
Minutes
Hours
RANGE
00–59
00–59
1–12
+AM/PM
00–23
1–7
01–31
01–12 +
Century
00–99
00–59
00–59
1–12 +
AM/PM
00–23
1–7
1–31
00–59
1–12 +
AM/PM
00–23
1–7
1–31
—
—
Seconds
Minutes
Hour
Note:
Unless otherwise specified, the state of the registers is not defined when power is first applied or V
CC
falls below the V
OSC
.
8 of 15
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
