HCS200
K
EE
L
OQ
®
Code Hopping Encoder*
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
28-bit serial number, 4-bit function code,
V
LOW
indicator transmitted
• Encryption keys are read protected
PACKAGE TYPES
PDIP, SOIC
S0
S1
S2
NC
1
HCS200
2
3
4
8
7
6
5
V
DD
NC
PWM
V
SS
Operating
• 3.5–13.0V operation
• Three button inputs
- seven functions available
• Selectable baud rate
• Automatic code word completion
• Battery low signal transmitted to receiver
• Non-volatile synchronization data
BLOCK DIAGRAM
Oscillator
Reset circuit
Controller
Power
latching
and
switching
Other
•
•
•
•
•
Easy to use programming interface
On-chip EEPROM
On-chip oscillator and timing components
Button inputs have internal pulldown resistors
Low external component cost
PWM
EEPROM
Encoder
32-bit shift register
Vss
V
DD
Button input port
Typical Applications
The HCS200 is ideal for Remote Keyless Entry (RKE)
applications. These applications include:
•
•
•
•
•
•
•
Fixed code replacement
Automotive RKE systems
Automotive alarm systems
Automotive immobilizers
Gate and garage door openers
Identity tokens
Burglar alarm systems
S2 S1 S0
The HCS200 combines a 32-bit hopping code
generated by a non-linear encryption algorithm, with a
28-bit serial number and 6 information bits to create a
66-bit transmission stream. The length of the
transmission eliminates the threat of code scanning,
and the code hopping mechanism makes each
transmission unique, thus rendering code capture and
resend schemes useless.
The encryption key, serial number, and configuration
data are stored in EEPROM which is not accessible via
any external connection. This makes the HCS200 a
very secure unit. The HCS200 provides an easy to use
serial interface for programming the necessary security
keys, system parameters, and configuration data.
All encryption keys and code combinations are pro-
grammable but read-protected. The keys can only be
verified after an automatic erase and programming
operation. This protects against attempts to gain
access to keys and manipulate synchronization values.
DESCRIPTION
The HCS200, from Microchip Technology Inc., is a code
hopping encoder designed for Remote Keyless Entry
(RKE) systems. The HCS200 utilizes the Keeloq
®
code
hopping technology, which incorporates high security, a
small package outline and low cost, to make this device
a perfect solution for replacement of fixed code devices
in unidirectional remote keyless entry systems and
access control systems.
KeeLoq is a trademark of Microchip Technology Inc.
*Code hopping encoder patents issued in Europe, U. S. A., and R. S. A.
©
1996 Microchip Technology Inc.
Preliminary
This document was created with FrameMaker 4 0 4
DS40138A-page 1
MICROCHIP [ MICROCHIP TECHNOLOGY ]
