DESCRIPTION
The HCS410 is a code hopping transponder device designed for secure entry systems. The HCS410 utilizes the patented KEELOQ® code hopping system and bi-directional challenge-and-response for logical and physical access control. High security learning mechanisms make this a turnkey solution when used with the KEELOQdecoders. The encoder keys and synchronization information are stored in protected on-chip EEPROM.

FEATURES
Security
• Two programmable 64-bit encoder keys
• 16/32-bit bi-directional challenge and response using one of two keys
• 69-bit transmission length
• 32-bit unidirectional code hopping, 37-bit non-encrypted portion
• Encoder keys are read protected
• Programmable 28/32-bit serial number
• 60/64-bit, read-protected seed for secure learning
• Three IFF encryption algorithms
• Delayed increment mechanism
• Asynchronous transponder communication
• Queuing information transmitted

Operating
• 2.0V - 6.6V operation, 13V encoder only operation
• Three switch inputs [S2, S1, S0]—seven functions
• Batteryless bi-directional transponder
• Selectable baud rate and code word blanking
• Automatic code word completion
• Battery low signal transmitted
• Non-volatile synchronization
• PWM or Manchester RF encoding
• Combined transmitter, transponder operation
• Anti-collision of multiple transponders
• Passive proximity activation
• Device protected against reverse battery
• Intelligent damping for high Q LC-circuits

Other
• 37-bit nonencrypted part contains 28/32-bit serial number, 4/0-bit function code, 1-bit battery low, 2-bit CRC, 2-bit queue
• Simple programming interface
• On-chip tunable RC oscillator (±10%)
• On-chip EEPROM
• 64-bit user EEPROM in transponder mode
• Battery-low LED indication
• SQTP serialization quick-time programming
• 8-pin PDIP/SOIC/TSSOP and die

Typical Applications
• Automotive remote entry systems
• Automotive alarm systems
• Automotive immobilizers
• Gate and garage openers
• Electronic door locks (Home/Office/Hotel)
• Burglar alarm systems
• Proximity access control