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