M
HCS500
Code Hopping Decoder
FEATURES
PACKAGE TYPE
PDIP, SOIC
Security
• Encrypted storage of manufacturer’s code
• Encrypted storage of encoder keys
• Up to seven transmitters can be learned
• KEELOQ code hopping technology
VDD
EE_CLK
EE_DAT
MCLR
1
2
3
4
8
7
6
5
VSS
RFIN
S_CLK
S_DAT
• Normal and secure learning mechanisms
Operating
• 3.0V—5.5V operation
• Internal oscillator
• Auto bit rate detection
BLOCK DIAGRAM
Other
RFIN
67-bit Reception Register
DECRYPTOR
S_DAT
• Stand-alone decoder chipset
• External EEPROM for transmitter storage
• Synchronous serial interface
• 1 Kbit user EEPROM
EE_DAT
EE_CLK
External
EEPROM
CONTROL
S_CLK
• 8-pin DIP/SOIC package
Typical Applications
MCLR
OSCILLATOR
• Automotive remote entry systems
• Automotive alarm systems
• Automotive immobilizers
• Gate and garage openers
• Electronic door locks
The manufacturer’s code, encoder keys, and synchro-
nization information are stored in encrypted form in
external EEPROM. The HCS500 uses the S_DAT and
S_CLK inputs to communicate with a host controller
device.
• Identity tokens
• Burglar alarm systems
The HCS500 operates over a wide voltage range of
3.0 volts to 5.5 volts. The decoder employs automatic
bit-rate detection, which allows it to compensate for
wide variations in transmitter data rate. The decoder
contains sophisticated error checking algorithms to
ensure only valid codes are accepted.
Compatible Encoders
• HCS200, HCS300, HCS301, HCS360,
HCS410 (PWM Mode)
DESCRIPTION
The Microchip Technology Inc. HCS500 is a code hop-
ping decoder designed for secure Remote Keyless
Entry (RKE) systems. The HCS500 utilizes the pat-
ented KEELOQ code hopping system and high security
learning mechanisms to make this a canned solution
when used with the HCS encoders to implement a uni-
directional remote and access control systems. The
HCS500 can be used as a stand-alone decoder or in
conjunction with a microcontroller.
KEELOQ is a registered trademark of Microchip Technology Inc.
*Code hopping patents issued in Europe, U.S.A; and R.S.—US:5,517,187; Europe: 0459781
1997 Microchip Technology Inc.
Preliminary
DS40153B-page 1