HCS201_11 MICROCHIP [Microchip Technology], HCS201_11 Datasheet - Page 6

• Manufacturer Part Number: HCS201_11
• Manufacturer: MICROCHIP [Microchip Technology]

HCS201
FIGURE 2-2:
DS41098D-page 6
Yes
RESET and Debounce Delay
Load Transmit Register
(A button has been pressed)
Word Transmission
Update Sync Info
Complete Code
Sample Inputs
Encrypt With
ENCODER OPERATION
Power-Up
Crypt Key
Released
Transmit
Buttons
(10 ms)
Buttons
Stop
Added
All
?
?
Yes
No
No
3.0
The HCS201 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, synchro-
nization value, etc. Further descriptions of the memory
array is given in the following sections.
TABLE 3-1:
3.1
The 64-bit crypt key is used to create the encrypted
message transmitted to the receiver. This key is calcu-
lated and programmed during production using a key
generation algorithm. The key generation algorithm
may be different from the K
the key generation algorithm are typically the transmit-
ter’s serial number and the 64-bit 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
decryption purposes.
3.2
This is the 16-bit synchronization value that is used to
create the hopping code for transmission. This value
will increment after every transmission.
ADDRESS
WORD
10
same
11
0
1
2
3
4
5
6
7
8
9
EEPROM MEMORY
ORGANIZATION
KEY_0 - KEY_3 (64-Bit Crypt Key)
SYNC (Synchronization Counter)
means
MNEMONIC
RESERVED Set to 0000H
CONFIG
SEED_0
SEED_1
EEPROM MEMORY MAP
KEY_0
KEY_1
KEY_2
KEY_3
SER_0
SER_1
SYNC
DISC
of
© 2011 Microchip Technology Inc.
EE
creating
L
64-bit encryption key
(word 0)
64-bit encryption key
(word 1)
64-bit encryption key
(word 2)
64-bit encryption key
(word 3)
16-bit synchronization
value
Device Serial Number
(word 0)
Device Serial Number
(word 1)
Seed Value (word 0)
Seed Value (word 1)
Discrimination Word
Config Word
OQ
DESCRIPTION
algorithm. Inputs to
the
key
for