DS1337 Maxim, DS1337 Datasheet - Page 8

• Manufacturer Part Number: DS1337
• Description: The DS1337 serial real-time clock is a low-power clock/calendar with two programmable time-of-day alarms and a programmable square-wave output
• Manufacturer: Maxim

ADDRESS MAP
Table 2
reaches the end of the register space (0Fh) it wraps around to location 00h. On an I
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
Note: Unless otherwise specified, the state of the registers is not defined when power is first applied or V
I
The I
while reading from the DS1337 during an I
terminate the last byte read with a Not-Acknowledge (NACK) to properly terminate the read. When the microcontroller
resets, the DS1337 I
high level. At that point the microcontroller should pull SDA low while SCL is high, generating a START condition.
2
ADDRESS
C INTERFACE
0AH
0BH
0CH
0DH
0EH
00H
01H
02H
03H
04H
05H
06H
07H
08H
09H
0FH
2
C interface is accessible whenever V
shows the address map for the DS1337 registers. During a multibyte access, when the address pointer
Century
EOSC
A1M1
A1M2
A1M3
A1M4
A2M2
A2M3
A2M4
BIT 7
OSF
0
0
0
0
0
2
C interface may be placed into a known state by toggling SCL until SDA is observed to be at a
DY/DT
DY/DT
12/24
12/24
12/24
BIT 6
0
0
0
0
0
10 Year
10 Seconds
10 Seconds
10 Minutes
10 Minutes
10 Minutes
10 Hour
10 Hour
10 Hour
AM/PM
AM/PM
AM/PM
BIT 5
0
0
0
0
10 Date
10 Date
10 Date
2
CC
C read, the two could become unsynchronized. The microcontroller must
is at a valid level. If a microcontroller connected to the DS1337 resets
10 Month
10 Hour
10 Hour
10 Hour
BIT 4
RS2
0
0
8 of 16
BIT 3
RS1
0
0
INTCN
BIT 2
0
Seconds
Seconds
Minutes
Minutes
Minutes
Month
Hour
Date
Year
Hour
Date
Hour
Date
Day
Day
BIT 1
A2IE
Day
A2F
DS1337 I
BIT 0
A1IE
A1F
2
C START, STOP, or address
2
CC
C Serial Real-Time Clock
FUNCTION
falls below the V
Seconds
Seconds
Minutes
Minutes
Minutes
Century
Alarm 1
Alarm 1
Alarm 1
Alarm 1
Alarm 1
Alarm 2
Alarm 2
Alarm 2
Alarm 2
Control
Month/
Status
Hours
Hours
Hours
Date
Year
Date
Date
Day
Day
Day
+AM/PM
RANGE
01–12 +
Century
AM/PM
AM/PM
1–12 +
1–12 +
00–59
00–59
00–23
01–31
00–99
00–59
00–59
00–23
01–31
00–59
00–23
01–31
1–12
OSC
1–7
1–7
1–7
—
—
.