hcs301 Microchip Technology Inc., hcs301 Datasheet - Page 4

• Manufacturer Part Number: hcs301
• Description: Keeloq Code Hopping Encoder
• Manufacturer: Microchip Technology Inc.

HCS301
FIGURE 1-2:
FIGURE 1-3:
NOTE: Circled numbers indicate the order of execution.
DS21143B-page 4
EEPROM Array
Serial Number
Sync Counter
Crypt Key
5
Perform Function
Indicated by
Button Press
button press
Information
BUILDING THE TRANSMITTED CODE WORD (ENCODER)
BASIC OPERATION OF RECEIVER (DECODER)
1
2
Received Information
Serial Number
Check for
Match
Synchronization
Encrypted Data
Decrypted
K
Decryption
Algorithm
32 Bits of
Counter
EE
Encryption
Algorithm
L
K
3
OQ
Button Press
EE
Information
L
OQ
Transmitted Information
Serial Number
4
Manufacturer Code
EEPROM Array
Check for
Serial Number
Match
Sync Counter
Crypt Key
2001 Microchip Technology Inc.
Encrypted Data
32 Bits