DS1372 Maxim, DS1372 Datasheet - Page 6

• Manufacturer Part Number: DS1372
• Description: The DS1372 is a 32-bit binary up counter and 24-bit down counter with a unique 64-bit ID
• Manufacturer: Maxim

I
The alarm counter is a 24-bit counter in the address
range 04h–06h. When the alarm counter is written, a
seed register is written with the alarm counter value.
When the alarm counter enable (ACE) bit in the Control
Register is set to 1, the counter begins counting down
from the seed value. When the counter reaches zero, it
sets the AF bit in the Status Register, if the AF bit is not
already set. If the AIE and INTCN bits are both set to a
logic 1, the SQW/INT pin goes low and remains low
until AF is written to logic 0. The counter is then
Table 1. DS1372 Address Map
Note: Unless otherwise specified, the states of the registers are undefined when power is first applied. Bits shown as 0 always read
back as 0.
6
2
ADDRESS
_______________________________________________________________________________________
C, 32-Bit, Binary Counter Clock with 64-Bit ID
0Ah
0Bh
0Ch
0Dh
00h
01h
02h
03h
04h
05h
06h
07h
08h
09h
0Eh
0Fh
10h
REGISTER
Control
Status
Clock
Clock
Clock
Clock
Alarm
Alarm
Alarm
ID
ID
ID
ID
ID
ID
ID
ID
Alarm Operation
BIT 7
MSB
MSB
OSF
—
—
—
—
—
BIT 6
ACE
0
BIT 5
0
0
reloaded with the seed value and the countdown
restarts. When the counter is read, the current counter
value is latched into a register, which is output on the
serial data line while the counter continues to decre-
ment. The counter is disabled if the seed value is zero
or if ACE = 0. Whenever the ACE is set from 0 to 1, the
counter is reloaded with the current seed value and the
counter begins to count down. Note: When initializing
or changing the alarm value, the ACE bit should be
enabled after writing the alarm counter bytes.
Seconds Counter Byte 0
Seconds Counter Byte 1
Seconds Counter Byte 2
Seconds Counter Byte 3
Alarm Counter Byte 0
Alarm Counter Byte 1
Alarm Counter Byte 2
Serial Number Byte 0
Serial Number Byte 1
Serial Number Byte 2
Serial Number Byte 3
Serial Number Byte 4
Serial Number Byte 5
BIT 4
Model Number
0
0
CRC
INTCN
BIT 3
0
BIT 2
RS2
0
BIT 1
RS1
0
BIT 0
LSB
LSB
AIE
AF
—
—
—
—
—