KEELOQ® HCS1XX/2XX/3XX
Encoder Family
The KEELOQ® family of encoders offers a complete range
of products for Remote Control and secure Remote
Keyless Entry (RKE) Applications. The encoders range
from the HCS101, a fixed code encoder designed for
remote control systems to the HCS2XX and HCS3XX
products, which utilize Microchip’s patented KEELOQ
hopping technology. The devices incorporates a small
package outline, low cost and the minimum external
components to make these device suited for unidirectional
remote keyless entry, remote control and access control
systems. The Code Hopping Encoders combine a 32-bit
hopping code generated by a non-linear encryption
algorithm, with a 32-bit serial number and information bits
to create a transmission stream of up to 69 bits. 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.
Security Features:
•Up to 2 programmable 32-bit serial numbers
•Up to 2 programmable 64-bit encoder keys
•Up to 2 programmable 60-bit seed values
•Each transmission is unique
•Up to 69-bit transmission code length
•32-bit hopping code
•Encoder keys are read protected
Operating Features:
•2.0 – 13.3V operation
•Up to six button inputs
•15 functions available
•Up to four selectable baud rates
•Selectable minimum code word completion
•Battery low signal transmitted to receiver
•Nonvolatile synchronization data
•PWM, VPWM, PPM and Manchester modulation
•Button queue information transmitted
•Dual Encoder functionality
Other Features:
•On-chip EEPROM
•On-chip tuned oscillator (±10%)
•Button inputs have internal pull-down resistors
•LED output
•PLL control for ASK and FSK
•Low external component count
Typical Applications:
•Automotive RKE systems
•Automotive alarm systems
•Automotive immobilizers
•Gate and garage door openers
•Identity tokens
•Burglar alarm systems
Related Application Notes:
•AN217 – KEELOQ HCS30X, HCS200 Stand-Alone
Programmer
•AN645 – PIC16C57 -Based Code Hopping
Security System
•AN661 – Code Hopping Decoder using PIC16C56
•AN662 – Code Hopping Decoder using Secure
Learn
•AN663 – Simple Code Hopping Decoder
•AN665 – Using KEELOQ to Generate Hopping
Passwords
•AN672 – PICmicro® Mid-range MCU Code
Hopping Decoder
•AN740 – Decoding the HCS101 for Non-Secure
Applications
•AN742 – Modular PICmicro Mid-Range Code
Hopping Decoder
•AN744 – Modular Mid-Range PICmicro KEELOQ
Decoder in C
•TB001 – Secure Learning RKE Systems using
KEELOQ Encoders
•TB003 – An Introduction to KEELOQ Code Hopping
•TB021 – A Guide to Designing for EuroHomelink
Compatibility
•TB042 – Interfacing a KEELOQ Encoder to a PLL
Circuit
•TB043 – KEELOQ CRC Verification Routines
