DS1200 Datasheet, PDF (1/7 Pages) Dallas Semiconductor – Serial RAM Chip

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FEATURES
§ 1024 Bits of Read/Write Memory
§ Low Data Retention Current for Battery
Backup Applications
§ Four Million Bits/Second Data Rate
§ Single-Byte or Multiple-Byte Data Transfer
Capability
§ No Restrictions on the Number of Write
Cycles
§ Low-Power CMOS Circuitry
APPLICATIONS
§ Software Authorization
§ Computer Identification
§ System Access Control
§ Secure Personnel Areas
§ Calibration
§ Automatic System Setup
§ Traveling Work Record
DS1200
Serial RAM Chip
PIN ASSIGNMENT
16-Pin SO (300mil)
See Mech. Drawings Section
PIN DESCRIPTION
V_CC
- +5V
RST
- Reset
DQ
- Data Input/Output
CLK
- Clock
GND
- Ground
V_BAT
NC
- Battery (+)
- No Connection
DESCRIPTION
The DS1200 serial RAM chip is a miniature read/write memory that can randomly access individual
8-bit strings (bytes) or sequentially access the entire 1024-bit contents (burst). Interface cost to a
microprocessor is minimized by on-chip circuitry, which permits data transfers with only three signals:
CLK, RST , and DQ.
Nonvolatility can be achieved by connecting a battery of 2V to 4V at the battery input V_BAT. A load of
0.5mA should be used to size the external battery for the required data retention time. If nonvolatility is
not required the V_BAT pin should be grounded.
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