ds1384 Maxim Integrated Products, Inc., ds1384 Datasheet
ds1384
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ds1384 Summary of contents
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... A “+” anywhere on the top mark indicates a lead-free/RoHS-compliant device. Watchdog Timekeeping Controller PIN CONFIGURATION TOP VIEW 44 1 INTB/(INTB) N.C. A14 A12 VOLTAGE (V) PIN-PACKAGE 5.0 44 MQFP 5.0 44 MQFP DS1384 34 33 A15 V BAT1 DS1384 WE A13 A8 A9 A11 OE A10 MQFP TOP MARK* DS1384FP DS1384FP REV: 112105 ...
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... RAM data in the absence of V the output enable to RAM (OER) are controlled during power transients to prevent data corruption. The DS1384 is a complete one-chip solution in that an external crystal and battery are the only components required to maintain time of day memory status in the absence of power. ...
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... CE is valid with WE disabled. When one of the 64 on-chip registers is selected during a read cycle, the OE is the enable signal for the DS1384 output buffers and the data bus is driven with read data. When the external RAM is selected during a read cycle, the OE signal is passed through to the OER pin so that read data is driven by the external SRAM ...
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... AOEL OPERATION—WRITE CYCLE The DS1384 is in the write mode whenever the WE (Write Enable) and CE (Chip Enable) signals are in the active (low) state after the address inputs are stable. The latter occurring falling edge will determine the start of the write cycle. The write cycle is terminated by the earlier rising edge ...
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... When the address value presented to the DS1384 during the write is in the range of 00000H through 0003FH, one of the 64 on-chip registers will be selected and data will be written into the device. When the address value presented to the DS1384 during the write is in the range of 00040H through 1FFFFH, an external SRAM location will be selected. ...
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... Figure 1. DS1384 Block Diagram ...
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... Figure 2. DS1384 Watchdog Timekeeper Registers ...
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Table 1. Time Of Day Alarm Mask Bits REGISTER MINUTES HOURS Note: any other bit combinations of mask bit settings produce illogical operation. TIME-OF-DAY REGISTERS Registers ...
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TIME-OF-DAY ALARM REGISTERS Registers 3, 5, and 7 contain the time of day alarm registers. Bits and 6 of register 7 will always read 0 regardless of how they are written. Bit 7 of registers 3, 5, ...
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Bit 3: WAM (Watchdog Alarm Mask). When this bit is set to a logic 0, the Watchdog Interrupt output will be activated. The activated state is determined by bits 1,4,5, and 6 of the Command Register. When this bit is ...
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ABSOLUTE MAXIMUM RATINGS Voltage Range on Any Pin Relative to Ground……………………………………………..-0.3V to +7.0V Operating Temperature Range………………………………………………………………..0°C to +70°C Storage Temperature Range………………………………………………………………..-20°C to +70°C Soldering Temperature………………………………………….See IPC/JEDEC J-STD-020 Specification This is a stress rating only and functional operation of the device ...
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AC ELECTRICAL CHARACTERISTICS (V = 5.0V ±10 0°C to +70°C PARAMETER Read Cycle Time Address Access Time CE Access Time CE Data Off Time Output Enable Access Time Output Enable Data Off Time Output Enable to ...
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CAPACITANCE (T = +25°C) A PARAMETER Capacitance on All Pins (Except DQ) Capacitance on DQ Pins AC ELECTRICAL CHARACTERISTICS (T = 0°C to +70°C) A PARAMETER before Power- IH Down V (Max (Min ...
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READ CYCLE TIMING—RTC AND EXTERNAL SRAM CONTROL SIGNALS ...
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OER TIMING WHEN SWITCHING BETWEEN LOWER MEMORY (00000h–0003Fh) AND UPPER MEMORY (00040h–1FFFFh) WRITE CYCLE TIMING—RTC AND EXTERNAL SRAM CONTROL SIGNALS ...
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POWER-UP TIMING DIAGRAM POWER-DOWN TIMING DIAGRAM ...
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... RAM in backup mode. The battery capacity (mA • hr) to achieve the formula BAT1 RAM at the battery voltage. For the DS1384 chip alone, a standard 48mAh lithium cell battery will provide greater than 10 years of data retention in the absence of power. 8) Applies to both interrupt pins when the alarms are set to pulse. ...
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... The Maxim logo is a registered trademark of Maxim Integrated Products, Inc. The Dallas logo is a registered trademark of Dallas Semiconductor Corporation © 2005 Maxim Integrated Products • Printed USA DS1384 ...