HCS410 HCS410 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 TSSOP S1 Programmable 28/32-bit serial number 2 7 LC1 S0 6 3 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 Address operation EEPROM Debounce Decoding S0 Wake-up Control Three switch inputs S2, S1, S0 seven functions 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 Driver Device protected against reverse battery 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. 2001 Microchip Technology Inc. Preliminary DS40158E-page 1 Transponder Circuitry Control Logic and Counters Encryption/Increment Logic RegisterHCS410 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 sev- eral 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. DS40158E-page 2 Preliminary 2001 Microchip Technology Inc.