DS2404 Datasheet, PDF (1/28 Pages) Dallas Semiconductor – EconoRAM Time Chip

DS2404
EconoRAM Time Chip
www.dalsemi.com
FEATURES
§ 4096 bits of nonvolatile dual-port memory
including real time clock/calendar in binary
format, programmable interval timer, and
programmable power-on cycle counter
§ 1-Wire^TM interface for MicroLAN
communication at 16.3k bits per second
§ 3-wire host interface for high-speed data
communications at 2M bits per second
§ Unique, factory-lasered and tested 64-bit
registration number (8-bit family code + 48-
bit serial number + 8-bit CRC tester) assures
absolute traceability because no two parts are
alike
§ Memory partitioned into 16 pages of 256-bits
for packetizing data
§ 256-bit scratchpad with strict read/write
protocols ensures integrity of data transfer
§ Programmable alarms can be set to generate
interrupts for interval timer, real time clock,
and/or cycle counter
§ 16-pin DIP, SOIC and SSOP packages
§ Operating temperature range from -40°C to
+85°C
§ Operating voltage range from 2.8 to 5.5
Volts
ORDERING INFORMATION
DS2404
16-pin DIP
DS2404S
16-pin SOIC
DS2404B
16-pin SSOP
PIN ASSIGNMENT
VCC
1
IRQ
2
RST
3
DQ
4
I/O
5
CLK
6
NC
7
GND 8
16 VCC
15 X1
14 X2
13 GND
12 NC
11 1HZ
10 VBATO
9 VBATB
16-PIN DIP (300 MIL)
16-PIN SOIC (300 MIL)
16-PIN SSOP (300 MIL)
See Mechanical Drawings Section
PIN DESCRIPTION
V_CC
– 2.8 to 5.5 Volts
IRQ
– Interrupt Output
RST
– 3-Wire Reset Input
DQ
– 3-Wire Input/Output
I/O
– 1-Wire Input/Output
CLK
– 3-Wire Clock Input
NC
– No Connection
GND
– Ground
V_BATB
V_BATO
1 Hz
– Battery Backup Input
– Battery Operate Input
– 1 Hz Output
X₁ ,X₂
– Crystal Connections
DESCRIPTION
The DS2404 EconoRAM Time Chip offers a simple solution for storing and retrieving vital data and time
information with minimal hardware. The DS2404 contains a unique lasered ROM, real-time
clock/calendar, interval timer, cycle counter, programmable interrupts and 4096-bits of SRAM. Two
separate ports are provided for communication, 1-Wire and 3-wire. Using the 1-Wire port, only one pin is
required for communication, and the lasered ROM can be read even when the DS2404 is without power.
The 3-wire port provides high speed communication using the traditional Dallas Semiconductor 3-wire
interface. With either interface, a strict protocol for accessing the DS2404 ensures data integrity. Utilizing
backup energy sources, the data is nonvolatile and allows for stand-alone operation.
The DS2404 features can be used to create a stopwatch, alarm clock, time and date stamp, logbook, hour
meter, calendar, system power cycle timer, expiration timer, and event scheduler.
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