µPD6121, 6122
4. REMOTE OUTPUT WAVEFORM (NEC TRANSMISSION FORMAT:
ONE-SHOT COMMAND TRANSMISSION MODE)
•
When fOSC = 455 kHz
(1) Remote (REM) output (from stage 2 , transmission occurs only when key is kept depressed)
REM output
58.5 to 76.5 ms
108 ms
1
108 ms
2
(2) Magnification of stage 1
3
REM output
9 ms
4.5 ms
Custom Code
8 bits
Custom Code’
8 bits
Data Code
8 bits
Data Code
8 bits
Stop Bit
1 bit
13.5 ms
Leader Code
18 ms to 36 ms
58.5 ms to 76.5 ms
27 ms
(3) Magnification of waveform 3
REM output
9 ms
4.5 ms
0.56 ms
1.125 ms 2.25 ms
13.5 ms
0
1
1
0
0
(4) Magnification of waveform 2
REM output
9 ms
2.25 ms
11.25 ms
0.56 ms
Stop Bit
Leader Code
(5) Carrier waveform (Magnification of HIGH period of codes)
REM output
8.77 µs
26.3 µs
9 ms or 0.56 ms
Carrier frequency: fc = fosc/12 = 38 kHz
Remark If a key is kept depressed, the second and subsequent times, only the leader code and the stop
bit are transmitted, which allows power savings for the infrared-emitting diode. If a command is
issued continuously in the same way the second and subsequent times as the first time, refer to
7. ONE-SHOT/CONTINUOUS COMMAND TRANSMISSION MODE.
11
NEC [ NEC ]
