DS1556W-120 Maxim Integrated Products, DS1556W-120 Datasheet - Page 9

• Manufacturer Part Number: DS1556W-120
• Description: IC RTC RAM Y2K 3.3V 120NS 32EDIP
• Manufacturer: Maxim Integrated Products
• Type: Clock/Calendar/NVSRAM/Y2Kr

Specifications of DS1556W-120

• Memory Size: 1M (128K x 8)
• Time Format: HH:MM:SS (24 hr)
• Date Format: YY-MM-DD-dd
• Interface: Parallel
• Voltage - Supply: 3 V ~ 3.6 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Through Hole
• Package / Case: 32-DIP Module (600 mil), 32-EDIP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

DS1556 1M, Nonvolatile, Y2K-Compliant Timekeeping RAM
Figure 3. Clearing IRQ Waveforms
CE=0
The IRQ/FT pin can also be activated in the battery-backed mode. The IRQ/FT will go low if an alarm
occurs and both ABE and AE are set. The ABE and AE bits are cleared during the power-up transition,
however an alarm generated during power-up will set AF. Therefore, the AF bit can be read after system
power-up to determine if an alarm was generated during the power-up sequence. Figure 4 illustrates alarm
timing during the battery-backup mode and power-up states.
Figure 4. Backup Mode Alarm Waveforms
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