|
|
PDF HCS300-ISN Data sheet ( Hoja de datos )
| Número de pieza | HCS300-ISN | |
| Descripción | KEE LOQ Code Hopping Encoder | |
| Fabricantes | Microchip Technology | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de HCS300-ISN (archivo pdf) en la parte inferior de esta página. Total 20 Páginas | ||
|
No Preview Available !
HCS300
Code Hopping Encoder*
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 KEELOQ
code hopping technology, which incorporates high secu-
rity, a small package outline and low cost, to make this
device a perfect solution for unidirectional remote key-
less entry systems and access control systems.
KeeLoq is a trademark of Microchip Technology Inc.
*Code hopping encoder patents allowed and pending.
PACKAGE TYPES
PDIP, SOIC
S0 1
S1 2
S2 3
S3 4
8 VDD
7 LED
6 PWM
5 VSS
HCS300 BLOCK DIAGRAM
Oscillator
LED
Reset circuit
LED driver
Controller
Power
latching
and
switching
PWM
EEPROM
Encoder
32-bit shift register
VSS
VDD
Button input port
S3 S2 S1 S0
The HCS300 combines a 32-bit hopping code
generated by a non-linear encryption algorithm, with a
28-bit serial number and six status bits to create a
66-bit transmission stream. The length of the
transmission eliminates the threat of code scanning
and the code hopping mechanism makes each
transmission unique, thus rendering code capture and
resend (code grabbing) schemes useless.
The encryption key, serial number, and configuration
data are stored in EEPROM which is not accessible via
any external connection. This makes the HCS300 a
very secure unit. The HCS300 provides an easy to use
serial interface for programming the necessary security
keys, system parameters, and configuration data.
The encyrption keys and code combinations are pro-
grammable but read-protected. The keys can only be
verified after an automatic erase and programming
operation. This protects against attempts to gain
access to keys and manipulate synchronization values.
© 1996 Microchip Technology Inc.
Preliminary
DS21137D-page 1
This document was created with FrameMaker 4 0 4
1 page  
FIGURE 2-2:
ENCODER OPERATION
Power Up
(A button has been pressed)
Reset and Debounce Delay
(10 ms)
Sample Inputs
Update Sync Info
Encrypt With
Encryption Key
Load Transmit Register
Transmit
Yes Buttons
Added
?
No
All
Buttons
Released
?
No
Yes
Complete Code
Word Transmission
Stop
HCS300
3.0 EEPROM MEMORY
ORGANIZATION
The HCS300 contains 192 bits (12 x 16-bit words) of
EEPROM memory (Table 3-1). This EEPROM array is
used to store the encryption key information,
synchronization value, etc. Further descriptions of the
memory array is given in the following sections.
TABLE 3-1: EEPROM MEMORY MAP
WORD
ADDRESS
MNEMONIC
DESCRIPTION
0 KEY_0
64-bit encryption key
(word 0)
1 KEY_1
64-bit encryption key
(word 1)
2 KEY_2
64-bit encryption key
(word 2)
3 KEY_3
64-bit encryption key
(word 3)
4 SYNC
16-bit synchronization
value
5 RESERVED Set to 0000H
6 SER_0
Device Serial Number
(word 0)
7 SER_1(Note) Device Serial Number
(word 1)
8
SEED_0
Seed Value (word 0)
9
SEED_1
Seed Value (word 1)
10 EN_KEY 16-bit Envelope Key
11 CONFIG Config Word
Note: The MSB of the serial number contains a bit
used to select the auto shutoff timer.
3.1 Key_0 - Key_3 (64-Bit Encryption Key)
The 64-bit encryption key is used by the transmitter to
create the encrypted message transmitted to the
receiver. This key is created and programmed at the
time of production using a key generation algorithm.
Inputs to the key generation algorithm are the serial
number for the particular transmitter being used and a
secret manufacturer’s code. While the key generation
algorithm supplied from Microchip is the typical method
used, a user may elect to create their own method of
key generation. This may be done providing that the
decoder is programmed with the same means of creat-
ing the key for decryption purposes. If a seed is used,
the seed will also form part of the input to the key gen-
eration algorithm.
© 1996 Microchip Technology Inc.
Preliminary
DS21137D-page 5
5 Page 
6.0 PROGRAMMING THE HCS300
When using the HCS300 in a system, the user will have
to program some parameters into the device including
the serial number and the secret key before it can be
used. The programming cycle allows the user to input
all 192 bits in a serial data stream, which are then
stored internally in EEPROM. Programming will be
initiated by forcing the PWM line high, after the S3 line
has been held high for the appropriate length of time
line (Table 6-1 and Figure 6-1). After the program mode
is entered, a delay must be provided to the device for
the automatic bulk write cycle to complete. This will
write all locations in the EEPROM to an all zeros pat-
tern. The device can then be programmed by clocking
in 16 bits at a time, using S3 as the clock line and PWM
as the data in line. After each 16-bit word is loaded, a
programming delay is required for the internal program
HCS300
cycle to complete. This delay can take up to Twc. At the
end of the programming 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.
Note:
To ensure that the device does not acci-
dentally enter programming mode, PWM
should never be pulled high by the circuit
connected to it. Special care should be
taken when driving PNP RF transistors.
FIGURE 6-1: PROGRAMMING WAVEFORMS
Enter Program
Mode
TPBW
TCLKH
TDS
S3
(Clock)
PWM
(Data)
TPS TPH1
TCLKL
TDH
Bit 0 Bit 1 Bit 2 Bit 3
Bit 14 Bit 15
TWC
Bit 16 Bit 17
TPH2
Data for Word 0 (KEY_0)
Repeat 12 times for each word
Note 1: Unused button inputs to be held to ground during the entire programming sequence.
Note 2: The VDD pin must be taken to ground after a program/verify cycle.
Data for Word 1
FIGURE 6-2: VERIFY WAVEFORMS
End of
Begin Verify Cycle Here
Programming Cycle
Data in Word 0
PWM
(Data)
Bit190 Bit191
S3
(Clock)
TWC
Bit 0
Bit 1 Bit 2 Bit 3
TDV
Bit 14
Bit 15
Bit 16 Bit 17
Note: If a Verify operation is to be done, then it must immediately follow the Program cycle.
Bit190 Bit191
© 1996 Microchip Technology Inc.
Preliminary
DS21137D-page 11
11 Page | ||
| Páginas | Total 20 Páginas | |
| PDF Descargar | [ Datasheet HCS300-ISN.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| HCS300-ISN | KEE LOQ Code Hopping Encoder | Microchip Technology |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |