DS32C35 Maxim Integrated Products, Inc., DS32C35 Datasheet - Page 13

• Manufacturer Part Number: DS32C35
• Description: Accurate I2c Rtc With Integrated Tcxo/crystal/fram
• Manufacturer: Maxim Integrated Products, Inc.

The DS32B35/DS32C35 contain two time-of-day/date
alarms. Alarm 1 can be set by writing to registers 07h
to 0Ah. Alarm 2 can be set by writing to registers 0Bh
to 0Dh. The alarms can be programmed (by the alarm
enable and INTCN bits of the Control register) to acti-
vate the INT/SQW output on an alarm match condition.
Bit 7 of each of the time-of-day/date alarm registers are
mask bits (Table 4). When all the mask bits for each
alarm are logic 0, an alarm only occurs when the values
in the timekeeping registers match the corresponding
values stored in the time-of-day/date alarm registers.
The alarms can also be programmed to repeat every
second, minute, hour, day, or date. Table 4 shows the
Table 4. Alarm Mask Bits
DY/DT
DY/DT
X
X
X
X
X
X
X
0
1
0
1
A1M4
1
1
1
1
0
0
A2M4
ALARM 1 REGISTER MASK BITS (BIT 7)
ALARM 2 REGISTER MASK BITS (BIT 7)
1
1
1
0
0
A1M3
1
1
1
0
0
0
Accurate I
A2M3
____________________________________________________________________
1
1
0
0
0
A1M2
Alarms
1
1
0
0
0
0
A2M2
A1M1
1
0
0
0
0
1
0
0
0
0
0
2
possible settings. Configurations not listed in the table
will result in illogical operation.
The DY/DT bits (bit 6 of the alarm day/date registers)
control whether the alarm value stored in bits 0 to 5 of
that register reflects the day of the week or the date of
the month. If DY/DT is written to logic 0, the alarm is the
result of a match with date of the month. If DY/DT is
written to logic 1, the alarm is the result of a match with
day of the week.
When the RTC register values match alarm register set-
tings, the corresponding Alarm Flag (“A1F”) or (“A2F”)
bit is set to logic 1. If the corresponding alarm interrupt
enable (“A1IE”) or (“A2IE”) is also set to logic 1 and the
INTCN bit is set to logic 1, the alarm condition will acti-
vate the INT/SQW signal.
C RTC with Integrated
Alarm once per second.
Alarm when seconds match.
Alarm when minutes and seconds match.
Alarm when hours, minutes, and seconds match.
Alarm when date, hours, minutes, and seconds match.
Alarm when day, hours, minutes, and seconds match.
Alarm once per minute (00 seconds of every minute).
Alarm when minutes match.
Alarm when hours and minutes match.
Alarm when date, hours, and minutes match.
Alarm when day, hours, and minutes match.
TCXO/Crystal/FRAM
ALARM RATE
ALARM RATE
13