DS1284 Maxim Integrated Products, DS1284 Datasheet - Page 8

• Manufacturer Part Number: DS1284
• Description: IC TIMEKEEPER WATCHDOG 28-DIP
• Manufacturer: Maxim Integrated Products
• Type: Watchdog Timerr

Specifications of DS1284

• Memory Size: 50B
• Time Format: HH:MM:SS:hh (12/24 hr)
• Date Format: YY-MM-DD-dd
• Interface: Parallel
• Voltage - Supply: 4.5 V ~ 5.5 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Through Hole
• Package / Case: 28-DIP (0.600", 15.24mm)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

interrupt output goes to the active state, which is determined by bits 0, 4, 5, and 6 of the command
register.
Bit 1: Watchdog Alarm Flag (WAF). When this bit is set internally to logic 1, a watchdog alarm has
occurred. This bit is read-only and writing this register has no effect on the bit. The bit is reset when any
of the watchdog alarm registers are accessed. The WAM bit has no effect on the operation of this bit. If
pulse mode (PU/LVL = 1) is selected, the watchdog continues to run and the flag is internally written to 0
at the end of the pulse. The WAM bit has no effect on the operation of this bit.
Bit 0: Time-of-Day Alarm Flag (TDF). When this bit is set internally to a logic 1, indicates that a match
with the time-of-day alarm registers has occurred. This bit is read-only and writing this register has no
effect on the bit. The time of the alarm can be determined by reading the time-of-day alarm registers. The
bit is reset when any of the time-of-day alarm registers are read. The TDM bit has no effect on the
operation of this bit.
Figure 3. Time-of-Day Alarm Mask Bits
MINUTES
(03h)
1
0
0
0
REGISTER
HOURS
(05h)
1
1
0
0
DAYS
(07h)
1
1
1
0
Alarm once per minute
Alarm when minutes match
Alarm when hours and minutes match
Alarm when hours, minutes, and days match
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FUNCTION
DS1284/DS1286