DS1678+ Maxim Integrated Products, DS1678+ Datasheet
DS1678+
Specifications of DS1678+
Related parts for DS1678+
DS1678+ Summary of contents
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... ORDERING INFORMATION DS1678 DS1678+ DS1678S DS1678S+ DS1678S/T&R DS1678S+T&R † All devices are specified over the -40°C to +85°C operating V CC range. INT †† A “‘+” anywhere on the top mark denotes a lead(Pb)-free SCL device ...
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ABSOLUTE MAXIMUM RATINGS Voltage Range on Any Pin Relative to Ground……………………………………………..-0.3V to +6.0V Operating Temperature Range (noncondensing)…………………………………………...-40°C to +85°C Storage Temperature Range…………………………………………………………….…-55°C to +125°C Soldering Temperature………………………………………….See IPC/JEDEC J-STD-020 Specification This is a stress rating only and functional operation of the ...
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AC ELECTRICAL CHARACTERISTICS (V = 2. 2.6V to 3.5V BAT PARAMETER SYMBOL Input Capacitance Minimum Signal Width Minimum Event Rate AC ELECTRICAL CHARACTERISTICS (V = 4.5V to 5.5V -40C to +85C.) ...
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Note 1: Limits at -40C are guaranteed by design and not production tested. Note 2: All voltages referenced to ground. Note 3: After this period, the first clock pulse is generated. Note 4: A device must initially provide a hold ...
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BLOCK DIAGRAM OSCILLATOR CONTROL INT LOGIC SCL SERIAL SDA INTERFACE V CC POWER V BAT CONTROL GND 1Hz DIVIDER REAL-TIME CLOCK ADDRESS USER RAM REGISTER DATA LOG RAM PORT Dallas Semiconductor ...
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PIN DESCRIPTION PIN NAME Connections for Standard 32.768kHz Quartz Crystal. For greatest accuracy, the DS1678 must be used with a crystal that has a specified load capacitance of 12.5pF. There is no need for external capacitors or resistors. Note: X1 ...
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DETAILED DESCRIPTION The Event Counter Register contains the total number of events that have been logged in the current event-logging mission. The Event Counter Register also allows the user to determine if the data in the event-log memory has rolled ...
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POWER CONTROL The device is fully accessible and data can be written and read when V when V falls below V , the internal registers are blocked from any access. The device power switched from V to ...
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MEMORY The memory map in Figure 2 shows the general organization of the DS1678. As can be seen in the figure, the device memory is in one contiguous segment with a data port to access the event-log memory. 2 Because ...
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The user can write only to the RTC, control registers, and user NV RAM. The rest of the memory map is read-only from the user’s perspective. During an event-log mission, all the memory is read-only. A write terminates the mission. ...
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Figure 2. DS1678 RTC and Control Page MSB ADDRESS BIT 7 BIT 12/ Year 07 10 Century Seconds Alarm ...
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EVENT LOGGING When the DS1678 event-logging function is enabled, the device is said “event-log mission” until the event logging is stopped. An event can be triggered one of three ways depending on the settings of the ...
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Figure 3. Start Mission Flow Chart Start via Computer Mem Clr =1 yes Write the MIP bit The ME bit is Automatically Written Time/Date Stamp is Written ETC Starts Incrementing EC is Incremented no ...
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ROLLOVER HANDLING There are two options for dealing with the potential occurrence of a data overrun (i.e., more than 1024 total event logs in the event-log memory) (Figure 4). The first option is to enable rollovers. This is accomplished by ...
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Figure 4. Rollover Flow Chart EC is Incremented INT Input Activated Memory Full Rollover Enable = 1 ETC Written to Event 0 and Time/Date Stamp is Written ETC is Cleared no Continue to Monitor Input yes no Record Event in ...
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CLOCK, CALENDAR, AND ALARM The time and calendar information is accessed by reading/writing the appropriate register bytes. Note that some bits are set to zero. These bits always read zero regardless of how they are written. The contents of the ...
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SPECIAL-PURPOSE REGISTERS The following descriptions define the operation of the DS1678 special-purpose registers. CONTROL REGISTER (0Eh) MSB BIT 7 BIT 6 ME CLR Bit 7: Mission Enable (ME). This bit enables the device to begin a mission. The ME bit ...
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The event counter is not incremented when the ETC rolls over because a new event has not occurred. The ETC is incremented as the selected seconds, minutes, or hours register of ...
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Bit 3: Rollover (RO). This bit determines whether the data log function of the DS1678 rolls over or stops writing data to the event-log memory if the event-log memory is completely filled set to one, the event-log ...
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STATUS REGISTER (0Fh) MSB BIT 7 BIT 6 0 MEM CLR Bit 6: Memory Cleared (MEM CLR). This bit indicates that the Event-Log Memory, Event Counter, and Start Time Stamp registers are all cleared to zero. MEM CLR is cleared ...
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EVENT COUNTER REGISTER (3Ah–3Ch) This three-byte register set provides the number of events that have been logged during the current data- logging operation (also known as a “mission”). The contents of this register can be used by software to point ...
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SECURITY The DS1678 provides several measures to ensure data integrity for the end user. These security measures are intended to prevent third-party intermediaries from tampering with the data that has been stored in the event-log memory first security ...
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A device that acknowledges must pull down the SDA line during the acknowledge clock pulse in such a way that the SDA line is stable LOW during the HIGH period of the acknowledge-related clock pulse. Of course, setup and hold ...
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Figure 6. Data Transfer on I SDA MSB slave address SCL 1 2 START CONDITION 2 Figure Serial Communication with DS1678 W rite ...
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... Maxim/Dallas Semiconductor cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim/Dallas Semiconductor product. No circuit patent licenses are implied. Maxim/Dallas Semiconductor reserves the right to change the circuitry and specifications without notice at any time The Maxim logo is a registered trademark of Maxim Integrated Products, Inc. The Dallas logo is a registered trademark of Dallas Semiconductor Corporation. THETA-J C (° ...