HCS361_11 Datasheet, PDF (4/42 Pages) Microchip Technology – KEELOQ® Code Hopping Encoder incorporates high security,

HCS361
FIGURE 1-2:
BUILDING THE TRANSMITTED CODE WORD (ENCODER)
EEPROM Array
Crypt Key
Sync Counter
Serial Number
KEELOQ®
Encryption
Algorithm
Button Press
Information
Serial Number
32 Bits
Encrypted Data
Transmitted Information
FIGURE 1-3:
BASIC OPERATION OF RECEIVER (DECODER)
1 Received Information
Button Press
Information
Serial Number
32 Bits of
Encrypted Data
EEPROM Array
Manufacturer Code
2
Check for
Match
Perform Function
5
Indicated by
button press
3
KEELOQ®
Decryption
Algorithm
Decrypted
Synchronization
Counter
Serial Number
Sync Counter
Crypt Key
4
Check for
Match
NOTE: Circled numbers indicate the order of execution.
DS40146F-page 4
© 2011 Microchip Technology Inc.