DS1200
Serial RAM Chip
www.maxim-ic.com
FEATURES
搂
搂
搂
搂
搂
搂
搂
搂
搂
搂
搂
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搂
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
PIN ASSIGNMENT
16-Pin SO (300mil)
See Mech. Drawings Section
APPLICATIONS
Software Authorization
Computer Identification
System Access Control
Secure Personnel Areas
Calibration
Automatic System Setup
Traveling Work Record
PIN DESCRIPTION
V
CC
RST
DQ
CLK
GND
V
BAT
NC
- +5V
- Reset
- Data Input/Output
- Clock
- Ground
- 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
0.5
mA
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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