hcs370 Microchip Technology Inc., hcs370 Datasheet - Page 4

• Manufacturer Part Number: hcs370
• Description: Keeloq Code Hopping Encoder
• Manufacturer: Microchip Technology Inc.

HCS370
FIGURE 1-2:
FIGURE 1-3:
NOTE: Circled numbers indicate the order of execution.
DS41111D-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
Preliminary
K
Decryption
Algorithm
32 Bits of
Counter
EE
Encryption
Algorithm
L
K
3
OQ
Button Press
EE
Information
L
OQ
B0
B1
Transmitted Information
Serial Number
Manufacturer Code
4
EEPROM Array
Serial Number
Counter
Verify
Sync Counter
Crypt Key
2002 Microchip Technology Inc.
Encrypted Data
32 Bits