HCS512
®
KEELOQ Code Hopping Decoder
FEATURES
Security
DESCRIPTION
The Microchip Technology Inc. HCS512 is a code hop-
ping decoder designed for secure Remote Keyless
Entry (RKE) systems. The HCS512 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 keyless entry system.
• Secure storage of Manufacturer’s Code
• Secure storage of transmitter’s keys
• Up to four transmitters can be learned
• KEELOQ code hopping technology
• Normal and secure learning mechanisms
PACKAGE TYPE
Operating
PDIP, SOIC
• 4.0V – 6.0V operation
• 4 MHz external RC oscillator
• Learning indication on LRNOUT
• Auto baud rate detection
• Power saving SLEEP mode
LRNIN
LRNOUT
NC
1
2
3
4
5
6
7
8
9
18
17
16
15
14
13
12
11
10
RFIN
NC
OSCIN
OSCOUT
VDD
MCLR
GND
S0
Other
• Stand-alone decoder
DATA
CLK
• On-chip EEPROM for transmitter storage
• Four binary function outputs–15 functions
• 18-pin DIP/SOIC package
S1
S2
SLEEP
VLOW
Typical Applications
S3
• Automotive remote entry systems
• Automotive alarm systems
• Automotive immobilizers
• Gate and garage openers
• Electronic door locks
BLOCK DIAGRAM
RFIN
Reception Register
DECRYPTOR
• Identity tokens
• Burglar alarm systems
DATA
EEPROM
CONTROL
CLK
Compatible Encoders
LRNIN
All KEELOQ encoders and transponders configured for
the following setting:
MCLR
SLEEP
OSCIN
OSCILLATOR
• PWM modulation format (1/3-2/3)
• TE in the range from 100 µs to 400 µs
• 10 x TE Header
OUTPUT
CONTROL
S3 VLOW LRNOUT
S2
S0 S1
• 28-bit Serial Number
The Manufacturer’s Code, transmitter keys, and syn-
chronization information are stored in protected on-
chip EEPROM. The HCS512 uses the DATA and CLK
inputs to load the Manufacturer’s Code which cannot
be read out of the device.
• 16-bit Synchronization counter
• Discrimination bits equal to Serial Number 8 LSbs
• 66- to 69-bit length code word.
2002 Microchip Technology Inc.
DS40151D-page 1