DS2417 Maxim, DS2417 Datasheet - Page 2

• Manufacturer Part Number: DS2417
• Description: The DS2417 1-Wire Time Chip with Interrupt offers a simple solution for storing and retrieving vital time information with minimal hardware
• Manufacturer: Maxim

OVERVIEW
The DS2417 has two main data components: 1) 64-bit lasered ROM, and 2) real-time clock counter
(Figure 1). The real-time clock utilizes an on-chip oscillator that is connected to an external 32.768kHz
crystal. The hierarchical structure of the 1-Wire protocol is shown in Figure 2. The bus master must first
provide one of four ROM function commands: 1) Read ROM, 2) Match ROM, 3) Search ROM, 4) Skip
ROM. The protocol for these ROM functions is described in Figure 7. After a ROM function command
is successfully executed, the real-time clock functions become accessible and the master may then
provide one of the real-time clock function commands. The protocol for these commands is described in
Figure 5. All data is read and written least significant bit first.
DETAILED PIN DESCRIPTION
BLOCK DIAGRAM Figure 1
PIN
5, 6
1
2
3
4
SYMBOL
X1, X2
1-Wire
GND
V
INT
DD
1-WIRE
V DD
DESCRIPTION
Ground Pin
Data input/output Open drain.
Interrupt pin Open drain.
Power input pin. 2.5V to 5.5V.
Crystal pins. Connections for a standard 32.768kHz quartz crystal, EPSON part
number C-002RX or C-004R (be sure to request 6pF load capacitance).
NOTE: X1 and X2 are very high impedance nodes. It is recommended that they
and the crystal be guard-ringed with ground and that high frequency signals be
kept away from the crystal area. See Figure 10 and Application Note 58 for de-
tails.
OSCILLATOR
CONTROL
FUNCTION
CONTROL
CLOCK
FUNCTION
CONTROL
ROM
2 of 15
RTC COUNTER (32-BIT)
READ/WRITE BUFFER
INT. GENERATOR
OSC./DIVIDER
X1
32.768 kHz
LASERED
64-BIT
ROM
X2
1 Hz
INT\
INT