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1999 Microchip Technology Inc.
Preliminary
DS21137E-page 1
FEATURES
Security
• Programmable 28-bit serial number
• Programmable 64-bit encryption key
• Each transmission is unique
• 66-bit transmission code length
• 32-bit hopping code
• 34-bit fixed code (28-bit serial number,
4-bit button code, 2-bit status)
• Encryption keys are read protected
Operating
• 2.0—6.3V operation
• Four button inputs
• No additional circuitry required
• 15 functions available
• Selectable baud rate
• Automatic code word completion
• Battery low signal transmitted to receiver
• Non-volatile synchronization data
Other
• Easy to use programming interface
• On-chip EEPROM
• On-chip oscillator and timing components
• Button inputs have internal pulldown resistors
• Current limiting on LED output
• Minimum component count
• Synchronous transmission mode
Typical Applications
The HCS300 is ideal for Remote Keyless Entry (RKE)
applications. These applications include:
• Automotive RKE systems
• Automotive alarm systems
• Automotive immobilizers
• Gate and garage door openers
• Identity tokens
• Burglar alarm systems
DESCRIPTION
The HCS300 from Microchip Technology Inc., is a code
hopping encoder designed for secure Remote Keyless
Entry (RKE) systems. The HCS300 utilizes the
®
code
hopping technology, which incorporates high security, a
small package outline and low cost to make this device
a perfect solution for unidirectional remote keyless
entry systems and access control systems.
PACKAGE TYPES
HCS300 BLOCK DIAGRAM
1
2
3
4
8
7
6
5
S0
S1
S2
S3
V
DD
LED
PWM
V
SS
PDIP, SOIC
H
C
S300
V
SS
V
DD
Oscillator
Reset circuit
LED driver
Controller
Power
latching
and
switching
Button input port
32-bit shift register
Encoder
EEPROM
PWM
LED
S
3
S
2
S
1
S
0
K
EE
L
OQ
®
Code Hopping Encoder
HCS300
K
EELOQ
is a registered trademark of Microchip Technology, Inc.
Microchip’s Secure Data Products are covered by some or all of the following patents:
Code hopping encoder patents issued in Europe, U.S.A., and R.S.A. — U.S.A.: 5,517,187; Europe: 0459781; R.S.A.: ZA93/4726
21137e.Book Page 1 Monday, October 4, 1999 8:04 AM