Microchip Technology KEELOQ HCS300 Manual Download

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1999 Microchip Technology Inc.

Preliminary

DS21137E-page 1

FEATURES

Security

• Programmable 28-bit serial number

• Programmable 64-bit encryption key

• Each transmission is unique

• 66-bit transmission code length

• 32-bit hopping code

• 34-bit fixed code (28-bit serial number,

4-bit button code, 2-bit status)

• Encryption keys are read protected

Operating

• 2.0—6.3V operation

• Four button inputs

• No additional circuitry required

• 15 functions available

• Selectable baud rate

• Automatic code word completion

• Battery low 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 pulldown resistors

• Current limiting on LED output

• Minimum component count

• Synchronous transmission mode

Typical Applications

The HCS300 is ideal for Remote Keyless Entry (RKE)
applications. These applications include:

• Automotive RKE systems

• Automotive alarm systems

• Automotive immobilizers

• Gate and garage door openers

• Identity tokens

• Burglar alarm systems

DESCRIPTION

The HCS300 from Microchip Technology Inc., is a code
hopping encoder designed for secure Remote Keyless
Entry (RKE) systems. The HCS300 utilizes the

code

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.

PACKAGE TYPES

HCS300 BLOCK DIAGRAM

LED

PWM

PDIP, SOIC

S300

Oscillator

Reset circuit

LED driver

Controller

Power
latching
and
switching

Button input port

32-bit shift register

Encoder

EEPROM

PWM

LED

Code Hopping Encoder

HCS300

EELOQ

is a registered trademark of Microchip Technology, Inc.

Microchip’s Secure Data Products are covered by some or all of the following patents:

Code hopping encoder patents issued in Europe, U.S.A., and R.S.A. — U.S.A.: 5,517,187; Europe: 0459781; R.S.A.: ZA93/4726

21137e.Book Page 1 Monday, October 4, 1999 8:04 AM

Summary of Contents for KEELOQ HCS300

Page 1: ... These applications include Automotive RKE systems Automotive alarm systems Automotive immobilizers Gate and garage door openers Identity tokens Burglar alarm systems DESCRIPTION The HCS300 from Microchip Technology Inc is a code hopping encoder designed for secure Remote Keyless Entry RKE systems The HCS300 utilizes the code hopping technology which incorporates high security a small package outl...

Page 2: ...ue and the synchronization counter 1 1 2 SECURE LEARN The transmitter is activated through a special button combination to transmit a stored 48 bit value random seed that can be used for key generation or be part of the key Transmission of the random seed can be dis abled after learning is completed The HCS300 is a code hopping encoder device that is designed specifically for keyless entry systems...

Page 3: ... is explained in detail in Section 4 2 Any type of controller may be used as a receiver but it is typically a microcontroller with compatible firmware that allows the receiver to operate in conjunction with a transmitter based on the HCS300 Section 7 0 provides more detail on integrating the HCS300 into a total system Before a transmitter can be used with a particular receiver the transmitter must...

Page 4: ...Information Encryption EEPROM Array 32 Bits of Encrypted Data Serial Number Transmitted Information Encryption Key Sync Counter Serial Number Button Press Information EEPROM Array Encryption Key 32 Bits of Encrypted Data Serial Number Received Information Decrypted Synchronization Counter Check for Match Check for Match KEELOQ Algorithm Decryption Sync Counter Serial Number Manufacturer Code ...

Page 5: ...n is pushed again Keeping a button pressed for a long time will result in the same code word being transmitted until the button is released or timeout occurs A code that has been transmitted will not occur again for more than 64K transmissions This will provide more than 18 years of typical use before a code is repeated based on 10 operations per day Overflow information programmed into the encode...

Page 6: ...od used a user may elect to create their own method of key generation This may be done providing that the decoder is pro grammed with the same means of creating the key for decryption purposes If a seed is used the seed will also form part of the input to the key generation algo rithm Power Up Reset and Debounce Delay 10 ms Sample Inputs Update Sync Info Encrypt With Load Transmit Register Buttons...

Page 7: ... envelope encryption key is used to encrypt the serial number portion of the transmission if the envelope encryption option has been selected The envelope encryption algorithm is a different algorithm than the key generation or transmit encryption algorithm The EN_key is typically a random number and the same for all transmitters in a system 3 6 Configuration Word The configuration word is a 16 bi...

Page 8: ...nsmission is made up of several parts Figure 4 1 Each transmission is begun with a preamble and a header followed by the encrypted and then the fixed data The actual data is 66 bits which consists of 32 bits of encrypted data and 34 bits of fixed data Each transmission is followed by a guard period before another transmission can begin Refer to Table 8 4 for transmission timing requirements The en...

Page 9: ...ade up from two status bits four button bits and the 28 bit serial number The four button bits and the 28 bit serial number may be encrypted with the Envelope Key if the envelope encryption is enabled by the user FIGURE 4 1 CODE WORD TRANSMISSION FORMAT FIGURE 4 2 CODE WORD ORGANIZATION LOGIC 0 LOGIC 1 Bit Period Preamble Header Encrypted Portion of Transmission Fixed Portion of Transmission Guard...

Page 10: ...o transmit a higher amplitude transmission if the transmission length is shorter The FCC puts constraints on the average power that can be transmitted by a device and BACW effectively prevents continuous transmission by only allowing the transmis sion of every second or every fourth code word This reduces the average power transmitted and hence assists in FCC approval of a transmitter device 5 3 E...

Page 11: ...in a pocket or purse This func tion can be enabled or disabled and is selected by set ting or clearing the Auto shutoff bit see Section 3 3 1 Setting this bit high will enable the function turn Auto shutoff function on and setting the bit low will disable the function Time out period is approximately 25 sec onds FIGURE 5 1 BLANK ALTERNATE CODE WORD BACW S3 S2 S1 S0 Notes 1 0 0 0 1 1 2 0 0 1 0 1 3 ...

Page 12: ...ion is set This VLOW signal is transmitted so the receiver can give an audible signal to the user that the transmitter battery is low Section 5 8 5 7 RPT Repeat Indicator This bit will be low for the first transmitted word If a button is held down for more than one transmitted code word this bit will be set to indicate a repeated code word and remain set until the button is released Figure 8 4 5 8...

Page 13: ...mming cycle the device can be veri fied Figure 6 2 by reading back the EEPROM Read ing is done by clocking the S3 line and reading the data bits on PWM For security reasons it is not possible to execute a verify function without first programming the EEPROM A verify operation can only be done once immediately following the program cycle FIGURE 6 1 PROGRAMMING WAVEFORMS FIGURE 6 2 VERIFY WAVEFORMS ...

Page 14: ...ameter Symbol Min Max Units Program mode setup time TPS 3 5 4 5 ms Hold time 1 TPH1 3 5 ms Hold time 2 TPH2 50 µs Bulk Write time TPBW 2 2 ms Program delay time TPROG 2 2 ms Program cycle time TWC 36 ms Clock low time TCLKL 25 µs Clock high time TCLKH 25 µs Data setup time TDS 0 µs Data hold time TDH 18 µs Data out valid time TDV 10 24 µs ...

Page 15: ...ck of these values for every transmitter that is learned Figure 7 1 The maximum number of transmitters that can be learned is only a function of how much EEPROM memory storage is available The decoder must also store the manufac turer s code in order to learn a transmission transmitter although this value will not change in a typical system so it is usually stored as part of the microcontroller RO...

Page 16: ...e double operation window of say 32K window the transmitted synchronization value is stored in tem porary location and it goes back to waiting for another transmission When the next valid transmission is received it will check the new value with the one in tem porary storage If the two values are sequential it is assumed that the counter had just gotten out of the sin gle operation window but is n...

Page 17: ...by current ICCS 0 1 1 0 0 1 1 0 µA Auto shutoff current3 4 ICCS 40 75 160 650 µA High level Input voltage VIH 0 55VDD VDD 0 3 0 55VDD VDD 0 3 V Low level input voltage VIL 0 3 0 15VDD 0 3 0 15VDD V High level output voltage VOH 0 7Vdd 0 7Vdd V V IOH 1 0 mA VDD 2 0V IOH 2 0 mA VDD 6 3V Low level output voltage VOL 0 08VDD 0 08VDD V V IOL 1 0 mA VDD 2 0V IOL 2 0 mA VDD 6 3V LED sink current5 ILED 1 ...

Page 18: ...ton detect TTD 10 26 ms Debounce delay TDB 6 13 ms Auto shutoff time out period TTO 20 35 s Note 2 Note 1 TBP is the time in which a second button can be pressed without completion of the first code word and the intention was to press the combination of buttons 2 The auto shutoff timeout period is not tested Button Press Sn Detect TDB PWM TTD Code Word Transmission TTO Code Word 1 Code Word 2 Code...

Page 19: ... 6 1 3 2 0 3 3 0 7 1 0 1 7 ms THOP Hopping code duration 96 25 0 38 4 63 4 12 5 19 2 31 7 6 2 9 6 15 8 ms TFIX Fixed code duration 102 26 5 40 8 67 3 13 3 20 4 33 7 6 6 10 2 16 8 ms TG Guard Time 39 10 1 15 6 25 7 5 1 7 8 12 9 2 5 3 9 6 4 ms Total Transmit Time 270 70 2 108 0 178 2 35 1 54 0 89 1 17 6 27 0 44 6 ms PWM data rate 1282 833 505 2564 1667 1010 5128 3333 2020 bps Note The timing paramet...

Page 20: ...300 P Data Sheets Products supported by a preliminary Data Sheet may have an errata sheet describing minor operational differences and recommended workarounds To determine if an errata sheet exists for a particular device please contact one of the following 1 Your local Microchip sales office 2 The Microchip Corporate Literature Center U S FAX 480 786 7277 3 The Microchip Worldwide Site www microc...

Page 21: ... 1999 Microchip Technology Inc Preliminary DS21137E page 21 HCS300 NOTES ...

Page 22: ...HCS300 DS21137E page 22 Preliminary 1999 Microchip Technology Inc NOTES ...

Page 23: ... 1999 Microchip Technology Inc Preliminary DS21137E page 23 HCS300 NOTES ...

Page 24: ...V 1W1 Canada Tel 905 405 6279 Fax 905 405 6253 ASIA PACIFIC Hong Kong Microchip Asia Pacific Unit 2101 Tower 2 Metroplaza 223 Hing Fong Road Kwai Fong N T Hong Kong Tel 852 2 401 1200 Fax 852 2 401 3431 Beijing Microchip Technology Beijing Unit 915 6 Chaoyangmen Bei Dajie Dong Erhuan Road Dongcheng District New China Hong Kong Manhattan Building Beijing 100027 PRC Tel 86 10 85282100 Fax 86 10 8528...

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