HCS360 Datasheet, PDF (11/24 Pages) Microchip Technology – KEELOQ CODE HOPPING ENCODER

HCS360
FIGURE 4-1: TRANSMISSION FORMAT—MANCH = 0
TOTAL TRANSMISSION:
1 CODE WORD
Preamble Sync ^Encrypt Fixed
Guard Preamble Sync Encrypt
CODE WORD:
LOGIC "0"
LOGIC "1"
TE
12 45 6
16
13579
13 14 15 2 4 6 8 10
TE
BIT
Preamble
Sync
Code Word
Encrypted
TX Data
Fixed Code
Data
Guard
Time
FIGURE 4-2: TRANSMISSION FORMAT—MANCH = 1
TOTAL TRANSMISSION:
1 CODE WORD
Preamble Sync Encrypt Fixed
Guard Preamble Sync Encrypt
CODE WORD:
TE
LOGIC "0"
LOGIC "1"
BPW
12 456
Start bit
16
13
13 14 15 ^{2 4}
Stop bit
Preamble
Sync
Encrypted
Data
CODE WORD
Fixed Code
Data
Guard
Time
FIGURE 4-3:
CRC
(2 bit)
CODE WORD ORGANIZATION (RIGHT-MOST BIT IS CLOCKED OUT FIRST)
Fixed Code Data
Encrypted Code Data
VLOW
(1 bit)
Button
Status
(4 bits)
28-bit
Serial Number
Button
Status
(4 bits)
Discrimination
bits
(12 bits)
16-bit
Synch Value
CRC VLOW
(2 bit) bit
+
Serial Number and
Button Status (32 bits)
MSB
LSB
67 bits
+
32 bits of Encrypted Data of Data
Transmitted
© 1996 Microchip Technology Inc.
Preliminary
DS40152C-page 11