DS1682_13 Datasheet, PDF (2/14 Pages) Dallas Semiconductor – Total-Elapsed-Time Recorder with Alarm

Figure 1. DS1682 Block Diagram
DS1682 Total-Elapsed-Time Recorder with Alarm
SCL
SDA
Dallas
Semiconductor
DS1682
V_CC
ALARM
EVENT
OSCILLATOR
AND
DIVIDER
CONTROL
LOGIC
AND
EVENT
GLITCH
FILTER
SERIAL
INTERFACE
USER, CONTROL, AND
CONFIGURATION
REGISTERS
ELAPSED TIME
COUNTER (ETC)
ALARM REGS
AND
COMPARE LOGIC
EVENT COUNTER
EEPROM ARRAY
PIN DESCRIPTION
PIN NAME
FUNCTION
Event Input. The EVENT pin is the input the DS1682 monitors to determine when
an event occurs. When the pin is pulled high, the contents of the EEPROM are
transferred to the ETC and the oscillator starts. The ETC begins to count in quarter-
1
EVENT
second increments. When the EVENT pin falls to logic 0, the event counter
increments, and the event counter, ETC, and user-memory data are stored in the
EEPROM array. When the EVENT pin changes states, the 2-wire bus is
unavailable for communications for t_EW (falling) and t_ER (rising). The EVENT input
is also deglitched (t_G) to prevent short noise spikes from triggering an event.
2, 7 N.C. No Connect. This pin is not connected internally.
Active-Low Alarm Output. The DS1682 monitors the values in the ETC for the
programmed value in the alarm register. When the ETC matches the alarm value,
3 ALARM the alarm flag (AF) is set. Once set, the alarm flag cannot be reset. See the
operating descriptions for the AOS and AP bits for details about the operation of
the ALARM pin.
4
GND Ground
2-Wire Serial-Clock Input. The SCL pin is the serial-clock input for the 2-wire
5
SCL synchronous communications channel. The SCL pin is an input that requires an
external pullup resistor.
2-Wire Input/Output. The SDA pin is the data input/output signal for the 2-wire
6
SDA synchronous communications channel. The SDA pin is an open-drain I/O, which
requires an external pullup resistor.
8
V_CC +2.5V to +5.5V Input Supply
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