Rainbow Electronics DS1603 - Manual

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FEATURES
§ Two 32-bit counters keep track of real-time
and elapsed time
§ Counters keep track of seconds for over 125
years
§ Battery powered counter counts seconds from
the time battery is attached until V
BAT
is less
than 2.5V
§ V
CC
powered counter counts seconds while
V
CC
is above V
T P
and retains the count in the
absence of V
CC
under battery backup power
§ Clear function resets selected counter to 0
§ Read/write serial port affords low pin count
§ Powered internally by a lithium energy cell
that provides over 10 years of operation
§ One-byte protocol defines read/write, counter
address and software clear function
§ Self-contained crystal provides an accuracy of
±2 min per month
§ Operating temperature range of 0°C to +70°C
§ Low-profile SIP module
§ Underwriters Laboratory (UL) recognized
PIN ASSIGNMENT
PIN DESCRIPTION
RST - Reset
CLK - Clock
DQ - Data Input/Output
GND - Ground
V
CC
- +5V
OSC - 1Hz Oscillator Output
NC - No Connect
DESCRIPTION
The DS1603 is a real-time clock/elapsed time counter designed to count seconds when V
CC
power is
applied and continually count seconds under battery backup power with an additional counter regardless
of the condition of V
CC
. The continuous counter can be used to derive time of day, week, month, and year
by using a software algorithm. The V
CC
powered counter will automatically record the amount of time
that V
CC
power is applied. This function is particularly useful in determining the operational time of
equipment in which the DS1603 is used. Alternatively, this counter can also be used under software
control to record real-time events. Communication to and from the DS1603 takes place via a 3-wire serial
port. A 1-byte protocol selects read/ write functions, counter clear functions and oscillator trim. The
device contains a 32.768kHz crystal that will keep track of time to within
±
2 min/mo. An internal lithium
energy source contains enough energy to power the continuous seconds counter for over 10 years.
OPERATION
The main elements of the DS1603 are shown in Figure 1. As shown, communications to and from the
elapsed time counter occur over a 3-wire serial port. The port is activated by driving RST to a high state.
1
2
3
4
5
6
7
V
CC
RST
DQ
NC
CLK
OSC
GND
DS1603
Elapsed Time Counter Module
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