DS1683_12 Datasheet, PDF (19/21 Pages) Maxim Integrated Products – Total-Elapsed-Time and Event Recorder with Alarm

DS1683
Total-Elapsed-Time and Event Recorder with Alarm
of this phenomenon by repeatedly addressing the
DS1683, which allows communication to continue
as soon as the DS1683 is ready. The alternative to
acknowledge polling is to wait for a maximum period
of t_W to elapse before attempting to access the device.
EEPROM Write Cycles: The DS1683’s EEPROM
write cycles are specified in the Nonvolatile Memory
Characteristics table. The specification shown is at
the worst-case temperature (hot). It can handle many
additional writes at room temperature.
Reading a Single Byte from a Slave: Unlike the write
operation that uses the specified memory address
byte to define where the data is to be written, the read
operation occurs at the present value of the memory
address counter. To read a single byte from the slave,
the master generates a START condition, writes the
slave address byte with R/W = 1, reads the data byte
with a NACK to indicate the end of the transfer, and
generates a STOP condition. However, since requiring
the master to keep track of the memory address coun-
ter is impractical, the following method should be used
to perform reads from a specified memory location.
Manipulating the Address Counter for Reads: A
dummy write cycle can be used to force the address
counter (or pointer) to a particular value. To do this, the
master generates a START condition, writes the slave
address byte (R/W = 0), writes the memory address
where it desires to read, generates a repeated START
condition, writes the slave address byte (R/W = 1),
reads data with ACK or NACK as applicable, and
generates a STOP condition. Recall that the master
must NACK the last byte to inform the slave that no
additional bytes will be read. See Figure 9 for I²C com-
munication examples.
Reading Multiple Bytes from a Slave: The read
operation can be used to read multiple bytes with a
single transfer. When reading bytes from the slave,
the master simply ACKs the data byte if it desires to
read another byte before terminating the transaction.
After the master reads the last byte it must NACK to
indicate the end of the transfer and generates a STOP
condition.
Applications Information
Power-Supply Decoupling
To achieve best results, it is recommended that the power
supply is decoupled with a 0.01FF or a 0.1FF capacitor.
Use high-quality, ceramic, surface-mount capacitors,
and mount the capacitors as close as possible to the V_CC
and GND pins to minimize lead inductance.
SDA and SCL Pullup Resistors
SDA is an open-collector output on the DS1683 that
requires a pullup resistor to realize high-logic levels. An
I²C master using either an open-collector output with
a pullup resistor or a push-pull output driver can be
used for SCL. Pullup resistor values should be chosen
to ensure that the rise and fall times listed in the I²C AC
Electrical Characteristics are within specification.
Maxim Integrated
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