DataSheet26.com

HCS500-IP PDF даташит

Спецификация HCS500-IP изготовлена ​​​​«Microchip Technology» и имеет функцию, называемую «KEELOQ CODE HOPPING ENCODER».

Детали детали

Номер произв HCS500-IP
Описание KEELOQ CODE HOPPING ENCODER
Производители Microchip Technology
логотип Microchip Technology логотип 

24 Pages
scroll

No Preview Available !

HCS500-IP Даташит, Описание, Даташиты
M
HCS500
Code Hopping Decoder
FEATURES
Security
• Encrypted storage of manufacturer’s code
• Encrypted storage of encoder keys
• Up to seven transmitters can be learned
• KEELOQ code hopping technology
• Normal and secure learning mechanisms
Operating
• 3.0V—5.5V operation
• Internal oscillator
• Auto bit rate detection
Other
• Stand-alone decoder chipset
• External EEPROM for transmitter storage
• Synchronous serial interface
• 1 Kbit user EEPROM
• 8-pin DIP/SOIC package
Typical Applications
• Automotive remote entry systems
• Automotive alarm systems
• Automotive immobilizers
• Gate and garage openers
• Electronic door locks
• Identity tokens
• Burglar alarm systems
Compatible Encoders
• HCS200, HCS300, HCS301, HCS360,
HCS410 (PWM Mode)
DESCRIPTION
The Microchip Technology Inc. HCS500 is a code hop-
ping decoder designed for secure Remote Keyless
Entry (RKE) systems. The HCS500 utilizes the pat-
ented KEELOQ code hopping system and high security
learning mechanisms to make this a canned solution
when used with the HCS encoders to implement a uni-
directional remote and access control systems. The
HCS500 can be used as a stand-alone decoder or in
conjunction with a microcontroller.
PACKAGE TYPE
PDIP, SOIC
VDD
EE_CLK
EE_DAT
MCLR
1
2
3
4
8 VSS
7 RFIN
6 S_CLK
5 S_DAT
BLOCK DIAGRAM
RFIN
67-bit Reception Register
External
EEPROM
EE_DAT
EE_CLK
CONTROL
DECRYPTOR
S_DAT
S_CLK
OSCILLATOR
MCLR
The manufacturer’s code, encoder keys, and synchro-
nization information are stored in encrypted form in
external EEPROM. The HCS500 uses the S_DAT and
S_CLK inputs to communicate with a host controller
device.
The HCS500 operates over a wide voltage range of
3.0 volts to 5.5 volts. The decoder employs automatic
bit-rate detection, which allows it to compensate for
wide variations in transmitter data rate. The decoder
contains sophisticated error checking algorithms to
ensure only valid codes are accepted.
KEELOQ is a registered trademark of Microchip Technology Inc.
*Code hopping patents issued in Europe, U.S.A; and R.S.—US:5,517,187; Europe: 0459781
© 1997 Microchip Technology Inc.
Preliminary
DS40153B-page 1









No Preview Available !

HCS500-IP Даташит, Описание, Даташиты
HCS500
1.0 KEELOQ SYSTEM OVERVIEW
1.1 Key Terms
• Manufacturer’s Code – A 64-bit word, unique to
each manufacturer, used to produce a unique
encoder key in each transmitter.
• Encoder Key – A 64-bit key, unique for each trans-
mitter. The encoder key controls the KeeLoq
decryption algorithm and is stored in EEPROM on
the decoder device.
• Learn – The receiver uses information that is
transmitted to derive the transmitter’s encoder key,
decrypt the discrimination value, and the synchro-
nization counter in learning mode. The encoder
key is a function of the manufacturer’s code and
the device serial number and/or seed value.
The HCS encoders and decoders employ the KeeLoq
code hopping technology and a KeeLoq encryption
algorithm to achieve a high level of security. Code
hopping is a method by which the code transmitted
from the transmitter to the receiver is different every
time a button is pushed. This method, coupled with a
transmission length of 66 bits, virtually eliminates the
use of code ‘grabbing’ or code ‘scanning’.
1.2 HCS Encoder Overview
The HCS encoders have a small EEPROM array which
must be loaded with several parameters before use.
The most important of these values are:
• An encoder key that is generated at the time of
production
• A 16-bit synchronization counter value
• A 28-bit serial number which is meant to be
unique for every encoder
The manufacturer programs the serial number for each
encoder at the time of production, while the ‘Key Gen-
eration Algorithm’ generates the encoder key (Figure 1-
1). Inputs to the key generation algorithm typically con-
sist of the encoder’s serial number and a 64-bit manu-
facturer’s code, which the manufacturer creates.
Note:
The manufacturer code is a pivotal part of
the system’s overall security. Conse-
quently, all possible precautions must be
taken and maintained for this code.
FIGURE 1-1: CREATION AND STORAGE OF ENCRYPTION KEY DURING PRODUCTION
Transmitter
Serial Number or
Seed
Manufacturer’s
Code
Key
Generation
Algorithm
Encryption
Key
HCS500 EEPROM Array
Serial Number
Encryption Key
Sync Counter
.
.
.
DS40153B-page 2
Preliminary
© 1997 Microchip Technology Inc.









No Preview Available !

HCS500-IP Даташит, Описание, Даташиты
HCS500
The 16-bit synchronization counter is the basis for the
transmitted code changing for each transmission and is
updated each time a button is pressed. Because of the
complexity of the KEELOQ encryption algorithm, a
change in one bit of the synchronization counter value
will result in a large change in the actual transmitted
code. There is a relationship (Figure 1-2) between the
encoder key values in EEPROM and how they are used
in the encoder. Once the encoder detects that a button
has been pressed, the encoder reads the button and
updates the synchronization counter. The synchroniza-
tion value is then combined with the encoder key in the
KEELOQ encryption algorithm, and the output is 32 bits
of encrypted information. This data will change with
every button press, hence, it is referred to as the code
hopping portion of the code word. The 32-bit code hop-
ping portion is combined with the button information
and the serial number to form the code word transmit-
ted to the receiver.
1.3 HCS Decoder Overview
Before a transmitter and receiver can work together, the
receiver must first ‘learn’ and store certain information
from the transmitter. This information includes a ‘check
value’ of the serial number, the encoder key, and cur-
rent synchronization counter value.
When a validly formatted message is detected, the
receiver first compares the serial number. If the serial
number check value is from a learned transmitter, the
message is decrypted. Next, the receiver checks the
decrypted synchronization counter value against what
is stored in memory. If the synchronization counter
value is verified, then a valid transmission message is
sent. Figure 1-3 shows the relationship between some
of the values stored by the receiver and the values
received from the transmitter.
FIGURE 1-2: BASIC OPERATION OF A CODE HOPPING TRANSMITTER (ENCODER)
Transmitted Information
EEPROM Array
Encoder Key
Sync. Counter Value
Serial Number
KEELOQ
Encryption
Algorithm
32 Bits of
Encrypted Data
Serial Number
Button Press
Information
FIGURE 1-3: BASIC OPERATION OF A CODE HOPPING RECEIVER (DECODER)
EEPROM Array
Encoder Key
Sync. Counter Value
Serial Number
Manufacturer Code
Check for
Match
KEELOQ
Decryption
Algorithm
Check for
Match
Decrypted
Synchronization
Counter
Button Press
Information
Serial Number
32 Bits of
Encrypted Data
Received Information
© 1997 Microchip Technology Inc.
Preliminary
DS40153B-page 3










Скачать PDF:

[ HCS500-IP.PDF Даташит ]

Номер в каталогеОписаниеПроизводители
HCS500-IPKEELOQ CODE HOPPING ENCODERMicrochip Technology
Microchip Technology
HCS500-ISMKEELOQ CODE HOPPING ENCODERMicrochip Technology
Microchip Technology

Номер в каталоге Описание Производители
TL431

100 мА, регулируемый прецизионный шунтирующий регулятор

Unisonic Technologies
Unisonic Technologies
IRF840

8 А, 500 В, N-канальный МОП-транзистор

Vishay
Vishay
LM317

Линейный стабилизатор напряжения, 1,5 А

STMicroelectronics
STMicroelectronics

DataSheet26.com    |    2020    |

  Контакты    |    Поиск