HCS412
KEELOQ Code Hopping Encoder and Transponder
FEATURES
PACKAGE TYPES
PDIP, SOIC
Security
S0
S1
1
2
3
4
8
7
6
5
VDD
• Programmable 64-bit encoder crypt key
• Two 64-bit IFF keys
LED
DATA
GND
• Keys are read protected
S2/RFEN/LC1
LC0
• 32-bit bi-directional challenge and response using
one of two possible keys
• 69-bit transmission length
• 32-bit hopping code,
BLOCK DIAGRAM
• 37-bit nonencrypted portion
• Programmable 28/32-bit serial number
• 60-bit, read protected seed for secure learning
• Two IFF encryption algorithms
Oscillator
V
DD
Power
Control
Configuration Register
Address
• Delayed counter increment mechanism
• Asynchronous transponder communication
EEPROM
S0
S1
Debounce
Decoding
Wake-up
Logic
Control
and
• Transmissions include button Queuing
information
Queuer
Operating
LED
LED
Control
• 2.0V to 6.3V operation
• Three switch inputs: S2, S1, S0 – seven functions
• Battery-less bi-directional transponder capability
• Selectable baud rate and code word blanking
• Automatic code word completion
PPM
Detector
LC0
RFEN/S2/LC1
DATA
PPM
Manch.
Encoder
• Battery low detector
DATA
DATA
Driver
• PWM or Manchester data encoding
• Combined transmitter, transponder operation
• Anticollision of multiple transponders
• Passive proximity activation
Other
• Simple programming interface
• Device protected against reverse battery
• Intelligent damping for high Q LC-circuits
• 100 mVPP sensitive LC input
• On-chip tunable RC oscillator, ± 10%
• On-chip EEPROM
• 64-bit user EEPROM in Transponder mode
• Battery-low LED indication
Typical Applications
• Serialized Quick Turn Programming (SQTPSM
)
• Automotive remote entry systems
• Automotive alarm systems
• Automotive immobilizers
• 8-pin PDIP/SOIC
• RF Enable output
• ASK and FSK PLL interface option
• Built in LC input amplifier
• Gate and garage openers
• Electronic door locks (Home/Office/Hotel)
• Burglar alarm systems
• Proximity access control
2002 Microchip Technology Inc.
Preliminary
DS41099C-page 1