DS1339 I2C Serial Real-Time Clock
ADDRESS MAP
Figure 6 shows the address map for the DS1339 registers. During a multibyte access, when the address pointer
reaches the end of the register space (10h), it wraps around to location 00h. On an I2C 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.
Figure 6. Timekeeper Registers
ADDRESS
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
FUNCTION
RANGE
00H
01H
0
0
10 Seconds
Seconds
Seconds
Minutes
00–59
00–59
10 Minutes
Minutes
Hour
1–12
+AM/PM
00–23
1–7
AM/PM
02H
0
10 Hour
0
Hours
12/24
10 Hour
0
03H
04H
0
0
0
0
0
Day
Day
Date
10 Date
Date
01–31
01–12 +
Century
10
Month/
05H
06H
07H
Century
0
0
Month
Month
Century
10 Year
Year
Year
00–99
Alarm 1
Seconds
Alarm 1
Minutes
Alarm 1
Hours
A1M1
A1M2
10 Seconds
10 Minutes
Seconds
00–59
08H
09H
Minutes
Hour
00–59
1–12 +
AM/PM
00–23
AM/PM
10 Hour
A1M3
A1M4
10 Hour
12/24
Alarm 1
Day,
0AH
DY/DT
10 Date
Day, Date
1-7, 1-31
Alarm 1
Date
Alarm 2
Minutes
0BH
0CH
A2M2
A2M3
10 Minutes
Minutes
Hour
00–59
1–12 +
AM/PM
00–23
AM/PM
10 Hour
Alarm 2
Hours
10 Hour
12/24
Alarm 2
Day,
0DH
A2M4
10 Date
Day, Date
1–7, 1–31
DY/DT
Alarm 2
Date
0EH
0FH
EOSC
0
0
0
0
RS2
0
RS1
0
INTCN
A2IE
A2F
A1IE
A1F
Control
Status
OSF
0
Trickle
ROUT1 ROUT0
10H
TCS3
TCS2
TCS1
TCS0
DS1
DS0
Charger
Note: Unless otherwise specified, the state of the registers are not defined when power is first applied or when VCC and VBACKUP falls below the
VBACKUP(MIN)
.
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DALLAS [ DALLAS SEMICONDUCTOR ]
