HCS412_11 Datasheet, PDF (15/52 Pages) Microchip Technology – KEELOQ® Code Hopping Encoder and Transponder Burglar alarm systems

HCS412
FIGURE 3-8: RF ENABLE/ASK/FSK OPTIONS
AFSK = 0, RFEN = 1
SWITCH
S2/RFEN/LC1
DATA
Code Word Code Word Code Word
AFSK = 1, RFEN = 0
SWITCH
S2/RFEN/LC1
DATA
TTD TLEDON
Code Word Code Word Code Word
FIGURE 3-9: LED OPERATION
NORMAL OPERATION
SWITCH
DATA
Code Word Code Word Code Word
LED
TLEDON
LOW VOLTAGE OPERATION
TLEDOFF
SWITCH
DATA
Code Word Code Word Code Word
LED
TLEDL
FIGURE 3-10: LONG PREAMBLE ENABLED (LPRE)
First Code Word
TLPRE
Header
Consecutive Code Words
First Code Word
- Long Preamble
Second Code Word Third Code Word
- Normal Preamble - Normal Preamble
© 2011 Microchip Technology Inc.
DS41099D-page 15