參數(shù)資料
型號: HCS361-IP
廠商: Microchip Technology Inc.
英文描述: IC AC/DC CONV 5V 200MA SIP10
中文描述: 而Keeloq跳碼編碼器
文件頁數(shù): 15/24頁
文件大小: 343K
代理商: HCS361-IP
HCS361
1996 Microchip Technology Inc.
Preliminary
DS40146C-page 15
7.2
Decoder Operation
In a typical decoder operation (Figure 7-2), the key gen-
eration on the decoder side is done by taking the serial
number from a transmission and combining that with
the manufacturer’s code to create the same secret key
that was used by the transmitter. Once the secret key is
obtained, the rest of the transmission can be decrypted.
The decoder waits for a transmission and immediately
can check the serial number to determine if it is a
learned transmitter. If it is, it takes the encrypted portion
of the transmission and decrypts it using the stored key
It uses the discrimination bits to determine if the
decryption was valid. If everything up to this point is
valid, the synchronization value is evaluated.
FIGURE 7-2:
TYPICAL DECODER
OPERATION
7.3
Synchronization with Decoder
The K
EE
L
OQ
technology features a sophisticated
synchronization technique (Figure 7-3) which does not
require the calculation and storage of future codes. If
the stored counter value for that particular transmitter
and the counter value that was just decrypted are within
a formatted window of say 16, the counter is stored and
the command is executed. If the counter value was not
within the single operation window, but is within the
double operation window of say 32K window, the trans-
mitted synchronization value is stored in temporary
location and it goes back to waiting for another trans-
mission. When the next valid transmission is received,
it will check the new value with the one in temporary
storage. If the two values are sequential, it is assumed
that the counter had just gotten out of the single opera-
tion ‘window’, but is now back in sync, so the new syn-
chronization value is stored and the command
executed. If a transmitter has somehow gotten out of
the double operation window, the transmitter will not
work and must be relearned. Since the entire window
rotates after each valid transmission, codes that have
been used are part of the ‘blocked’ (32K) codes and are
no longer valid. This eliminates the possibility of grab-
bing a previous code and retransmitting to gain entry.
FIGURE 7-3:
SYNCHRONIZATION WINDOW
Transmission
Received
Does
Serial Number
Match
Decrypt Transmission
Is
Decryption
Valid
Is
Counter
Within 16
Is
Counter
Within 32K
Uand
Counter
Execute
Command
Save Counter
in Temp Location
Start
No
No
No
No
Yes
Yes
Yes
Yes
Yes
No
No
Note:
The synchronization method described in
this section is only a typical implementation
and because it is usually implemented in
firmware, it can be altered to fit the needs
of a particular system
Blocked
(32K Codes)
Entire Window
rotates to eliminate
use of previously
used codes
Current
Position
Double
Operation
(32K Codes)
Single Operation
Window (16 Codes)
相關PDF資料
PDF描述
HCS361-ISN IC CONV AC/DC -12V 90MA SIP9
HCS361-P IC CONV AC/DC -5V 100MA SIP9
HCS361-SN IC AC/DC CONV 12V 350MA SIP12
HCS365 KEELOQ Code Hopping Encoder
HCS365T KEELOQ Code Hopping Encoder
相關代理商/技術參數(shù)
參數(shù)描述
HCS361-ISN 制造商:MICROCHIP 制造商全稱:Microchip Technology 功能描述:KEELOQ CODE HOPPING ENCODER
HCS361-P 制造商:MICROCHIP 制造商全稱:Microchip Technology 功能描述:KEELOQ CODE HOPPING ENCODER
HCS361-SN 制造商:MICROCHIP 制造商全稱:Microchip Technology 功能描述:KEELOQ CODE HOPPING ENCODER
HCS361T/SN 功能描述:編碼器、解碼器、復用器和解復用器 2-6.6V RoHS:否 制造商:Micrel 產(chǎn)品:Multiplexers 邏輯系列:CMOS 位數(shù): 線路數(shù)量(輸入/輸出):2 / 12 傳播延遲時間:350 ps, 400 ps 電源電壓-最大:2.625 V, 3.6 V 電源電壓-最小:2.375 V, 3 V 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:QFN-44 封裝:Tray
HCS361T-I/SN 功能描述:編碼器、解碼器、復用器和解復用器 2-6.6V RoHS:否 制造商:Micrel 產(chǎn)品:Multiplexers 邏輯系列:CMOS 位數(shù): 線路數(shù)量(輸入/輸出):2 / 12 傳播延遲時間:350 ps, 400 ps 電源電壓-最大:2.625 V, 3.6 V 電源電壓-最小:2.375 V, 3 V 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:QFN-44 封裝:Tray