HCS410 HCS410 40158F.book Page 1 Wednesday, June 1, 2011 10:36 AM HCS410 KEELOQ Code Hopping Encoder and Transponder FEATURES PACKAGE TYPES Security PDIP, SOIC S018 VDD Two programmable 64-bit encoder keys 16/32-bit bi-directional challenge and response S1 2 7 LC0 using one of two keys S2/LED 3 6 PWM 69-bit transmission length 32-bit unidirectional code hopping, 37-bit non- LC1 4 5 GND encrypted portion Encoder keys are read protected 1 8 S2/LED S1 TSSOP Programmable 28/32-bit serial number 2 7 LC1 S0 3 6 GND VDD 60/64-bit, read-protected seed for secure learning 5 4 PWM LC0 Three IFF encryption algorithms Delayed increment mechanism BLOCK DIAGRAM Asynchronous transponder communication Oscillator Queuing information transmitted Power VDD Control Operating Configuration Register 2.0V - 6.6V operation, 13V encoder only operation Address EEPROM Debounce S0 Decoding Wake-up Three switch inputs S2, S1, S0 seven functions Control S1 Logic and Batteryless bi-directional transponder Queuer Selectable baud rate and code word blanking LED Automatic code word completion S2 Control Battery low signal transmitted Non-volatile synchronization PPM PWM or Manchester RF encoding Detector LCI0 Combined transmitter, transponder operation LCI1 PWM PPM Anti-collision of multiple transponders Manch. Encoder Passive proximity activation PWM PWM Device protected against reverse battery Driver Intelligent damping for high Q LC-circuits Typical Applications Other Automotive remote entry systems 37-bit nonencrypted part contains 28/32-bit serial Automotive alarm systems number, 4/0-bit function code, 1-bit battery low, 2-bit CRC, 2-bit queue Automotive immobilizers Simple programming interface Gate and garage openers On-chip tunable RC oscillator (10%) Electronic door locks (Home/Office/Hotel) On-chip EEPROM Burglar alarm systems 64-bit user EEPROM in transponder mode Proximity access control Battery-low LED indication SQTP serialization quick-time programming 8-pin PDIP/SOIC/TSSOP and die *Secure Learn patent pending. 2011 Microchip Technology Inc. DS40158F-page 1 Transponder Circuitry Control Logic and Counters Encryption/Increment Logic Register40158F.book Page 2 Wednesday, June 1, 2011 10:36 AM HCS410 DESCRIPTION 1.0 SYSTEM OVERVIEW The HCS410 is a code hopping transponder device 1.1 Key Terms designed for secure entry systems. The HCS410 uti- Anti-Collision Allows two transponders to be in lizes the patented KEELOQ code hopping system and the files simultaneously and be verified individu- bi-directional challenge-and-response for logical and ally. physical access control. High security learning mecha- nisms make this a turnkey solution when used with the CH Mode Code Hopping Mode. The HCS410 KEELOQ decoders. The encoder keys and synchroniza- transmits a 69-bit transmission each time it is acti- tion information are stored in protected on-chip vated, with at least 32-bits changing each time the EEPROM. encoder is activated. Encoder Key A unique 64-bit key generated and A low cost batteryless transponder can be imple- programmed into the encoder during the manu- mented with the addition of an inductor and two capac- facturing process. The encoder key controls the itors. A packaged module including the inductor and encryption algorithm and is stored in EEPROM on capacitor will also be offered. the encoder device. A single HCS410 can be used as an encoder for IFF Identify friend or foe is a means of validating Remote Keyless Entry (RKE) and a transponder for a token. A decoder sends a random challenge to immobilization in the same circuit and thereby dramat- the token and checks that the response of the ically reducing the cost of hybrid transmitter/transpon- token is a valid response. der circuits. KEELOQ Encryption Algorithm The high security level of the HCS410 is based on the patented KEELOQ technology. A block cipher encryption algorithm based on a block length of 32 bits and a key length of 64 bits is used. The algorithm obscures the information in such a way that even if the unencrypted/challenge information differs by only one bit from the information in the previous transmission/challenge, the next coded transmis- sion/response will be totally different. Statistically, if only one bit in the 32-bit string of information changes, approximately 50 percent of the coded transmission will change. Learn The HCS product family facilitates several learning strategies to be implemented on the decoder. The following are examples of what can be done. Normal Learn The receiver uses the same infor- mation that is transmitted during normal operation to derive the transmitters encoder key, decrypt the dis- crimination value and the synchronization counter. Secure Learn* The transmitter is activated through a special button combination to transmit a stored 60-bit value (random seed) that can be used for key generation or be part of the key. Transmission of the random seed can be disabled after learning is com- pleted. Manufacturers Code A 64-bit word, unique to each manufacturer, used to produce a unique encoder key in each transmitter (encoder). Passive Proximity Activation When the HCS410 is brought into in a magnetic field without a command given by the base station, the HCS410 can be programmed to give an RF transmission. Transport Code A 32-bit transport code needs to be given before the HCS410 can be inductively programmed. This prevents accidental programming of the HCS410. DS40158F-page 2 2011 Microchip Technology Inc.