**HCSxxx KeeLoq® Code Hopping Encoders/Decoders** The HCS series of KeeLoq encoders/decoders work with Ir or RF transmitter and receiver devices to make secure 3- or 4-button wireless remote control systems.
The HCS301-I/SN is a code Hopping Encoder, designed for secure remote keyless entry (RKE) systems. The HCS301 utilizes Microchip"s patented KEELOQ® hopping technology, which incorporates high security, a small package outline and low cost, to make this device a perfect solution for unidirectional remote keyless entry systems and access control systems. This combines a 32-bit hopping code generated by a non-linear encryption algorithm, with a 28-bit serial number and six status bits to create a 66-bit transmission stream. 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 re-send (code grabbing) schemes useless. The encryption key, serial number and configuration data are stored in EEPROM, which is not accessible via any external connection. This makes the HCS301 a very secure unit.
DESCRIPTION The HCS200 from Microchip Technology Inc. is a code hopping encoder designed primarily for Remote Key less Entry (RKE) systems. The device utilizes the KEELOQ® code hopping technology, incorporating high security, a small package outline and low cost. The HCS200 is a perfect replacement of fixed code devices in unidirectional remote keyless entry systems and access control systems. FEATURES Security • Programmable 28-bit serial number • Programmable 64-bit crypt key • Each transmission is unique • 66-bit transmission code length • 32-bit hopping code • 28-bit serial number, 4-bit button status, low battery indicator transmitted • Crypt keys are read protected Operating • 3.5–13.0V operation • Three button inputs - seven functions available • Selectable baud rate • Automatic code word completion • Low battery signal transmitted to receiver • Non-volatile synchronization data Other • Easy to use programming interface • On-chip EEPROM • On-chip oscillator and timing components • Button inputs have internal pull-down resistors • Low external component cost Typical Applications The HCS200 is ideal for Remote Keyless Entry (RKE) applications. These applications include: • Fixed code replacement • Automotive RKE systems • Automotive alarm systems • Automotive immobilizers • Gate and garage door openers • Identity tokens • Burglar alarm systems