HCS500
®
KEELOQ Code Hopping Decoder
FEATURES
Security
DESCRIPTION
The Microchip Technology Inc. HCS500 is a code
hopping decoder designed for secure Remote Keyless
Entry (RKE) systems. The HCS500 utilizes the
patented KEELOQ code hopping system and high-
security learning mechanisms to make this a canned
solution when used with the HCS encoders to
implement a unidirectional remote and access control
systems. The HCS500 can be used as a stand-alone
decoder or in conjunction with a microcontroller.
• Encrypted Storage of Manufacturer’s Code
• Encrypted Storage of Crypt Keys
• Up to Seven Transmitters can be Learned
• KEELOQ Code Hopping Technology
• Normal and Secure Learning Mechanisms
Operating
PIN DIAGRAM
• 3.0V—5.5V Operation
• Internal Oscillator
PDIP, SOIJ
• Auto Bit Rate Detection
VDD
EE_CLK
EE_DAT
MCLR
1
2
3
4
8
7
6
5
VSS
Other
RFIN
• Stand-Alone Decoder Chipset
• External EEPROM for Transmitter Storage
• Synchronous Serial Interface
• 1 Kbit user EEPROM
S_CLK
S_DAT
• 8-Pin PDIP/SOIJ Package
FIGURE 1:
BLOCK DIAGRAM
Typical Applications
RFIN
• Automotive Remote Entry Systems
• Automotive Alarm Systems
• Automotive Immobilizers
• Gate and Garage Openers
• Electronic Door Locks
Reception Register
DECRYPTOR
S_DAT
EE_DAT
EE_CLK
External
EEPROM
CONTROL
S_CLK
• Identity Tokens
• Burglar Alarm Systems
MCLR
OSCILLATOR
Compatible Encoders
All KEELOQ encoders and transponders configured for
the following setting:
The manufacturer’s code, crypt keys, and
synchronization 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.
• PWM Modulation Format (1/3-2/3)
• TE in the range from 100 us to 400 us
• 10 x TE Header
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.
• 28-Bit Serial Number
• 16-Bit Synchronization Counter
• Discrimination Bits Equal to Serial Number
8 LSbs
• 66- to 69-Bit Length Code Word.
2001-2015 Microchip Technology Inc.
DS40000153E-page 1