Owner's Manual

109
¶∞ƒ∞ƒ∆∏ª∞
∫ˆ‰ÈÎÔ› ˘ÂÚ‡ıÚˆÓ
A
Configuration of frame
1st frame
Repeat frame
A
Lead code
A
Repeat code
A
BBiitt ddeessccrriippttiioonn
A
FFrraammee iinntteerrvvaall:: TTff
The waveform is transmitted as long as a key is depressed.
C0 C1 C2 C3 C4 C5 C6 C7 C0 C1 C2 C3 C4 C5 C6 C7 D0 D1 D2 D3 D4 D5 D6 D7 D0 D1 D2 D3 D4 D5 D6 D7
Lead code Low custom code High custom code Data code Data code
Repeat code
Tf
4.5 ms
9 ms
2.25 ms
9 ms
0.55 ms
0.56 ms
1.12 ms
0.56 ms
2.24 ms
Tf Tf
Tf=108ms @455KHz
Bit ”0” Bit ”1”
1. ∆ÚfiÔ˜ Û‡Ó‰ÂÛ˘
■
™˘Ó‰¤ÛÙ ÙÔ ÂÓÛ‡ÚÌ·ÙÔ ÙËϯÂÈÚÈÛÙ‹ÚÈfi Û·˜ ÛÙËÓ ˘Ô‰Ô¯‹ ÙËϯÂÈÚÈÛÙËÚ›Ô˘ Ù˘ ÙËÏÂfiÚ·Û˘.
2. Kˆ‰ÈÎÔ› ˘ÂÚ‡ıÚˆÓ ÙËϯÂÈÚÈÛÙËÚ›Ô˘
■
™‹Ì· ÂÍfi‰Ô˘ Î˘Ì·ÙÔÌÔÚÊ‹˜
ªÔÓÔ·ÏÌÈÎfi, Ú˘ıÌÈṲ̂ÓÔ Ì ۋ̷ 37,917KHz ÛÙ· 455KHz
T1
Tc
™˘¯ÓfiÙËÙ· ÊÔÚ¤·
FCAR = 1/Tc = fOSC/12
Duty ratio = T1/Tc = 1/3