hcs412 Microchip Technology Inc., hcs412 Datasheet - Page 15

• Manufacturer Part Number: hcs412
• Description: Keeloq? Code Hopping Encoder And Transponder
• Manufacturer: Microchip Technology Inc.

FIGURE 3-8:
FIGURE 3-9:
FIGURE 3-10: LONG PREAMBLE ENABLED (LPRE)
2002 Microchip Technology Inc.
AFSK = , RFEN = 1
AFSK = 1, RFEN =
First Code Word
Consecutive Code Words
NORMAL OPERATION
LOW VOLTAGE OPERATION
S2/RFEN/LC1
S2/RFEN/LC1
SWITCH
SWITCH
SWITCH
SWITCH
DATA
DATA
LED
LED
DATA
DATA
RF ENABLE/ASK/FSK OPTIONS
LED OPERATION
First Code Word
- Long Preamble
T
TD
T
Code Word
LEDON
Code Word
T
LEDON
Code Word
Code Word
Code Word
Code Word
T
Preliminary
LEDOFF
Second Code Word
- Normal Preamble
T
LPRE
Code Word
Code Word
Code Word
Code Word
T
LEDL
Code Word
Code Word
Third Code Word
- Normal Preamble
Header
HCS412
DS41099C-page 15